ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Low On Cash on January 24, 2017, 08:05:46 AM
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I thought it would be a good discussion topic regarding proper long term battery storage and some of the options to help preserve our cells. Zero’s “Leave it Plugged In†recommendations has created considerable uncertainty regarding proper procedures during winter or non-use storage.
I’ll also discuss a commonly used “Self-Discharge†feature which self drains the cells to a lower SOC after a period of time, this is used on lithium cells for the aerial drone industry and may be advantageous to Zero owners as well.
Zero’s Plug & Leave Recommendations
Regretfully, I “Do Not†recommend using Zero’s storage recommendations outlined in the manual of just leaving the battery on charge and unattended. This is not a safe practice and certainly not in the best interest of protecting your home or bike.
For safety reasons - Or when ever possible, lithium cells should never be left on charge unattended, since in the event of a battery management system malfunction and failure to limit charging, it could result in catastrophic results and a fire.
Battery Management System - As we all know, the only safety valve to prevent under or over charging of the pack is the battery management circuitry. This system is not perfect and if a failure occurs there no redundant backup system to monitor battery status.
Speaking for myself, it is not even imaginable to leave my bike on charge and head down to Florida. The battery pack in our bikes is like a small bomb. I’m sure most of you have seen what happens with these electronic cigarettes when just one small cell ignites, so you can imagine a Zero pack.
Winter or work storage for me means unplugging everything possible to prevent the unknown from happening. Having my Zero’s battery charged is far less important that the safety of my home. Even for every day charging, I always attempt to charge when I get home and in most cases before bedtime she’s back up to 100%. While I understand this schedule might not work for everyone, if you have to leave the bike plugged in at night or when not home, there is a risk, so use caution.
Voltage Spikes - There is always concern for voltage spikes in the power grid which could damage the charger or BMS. In addition, spikes may cause the processor to freeze with uncertain results causing an overcharge situation.
During a lightning storm, a close proximity strike could easily destroy not only the charging circuit, but also spike the bikes processor and circuitry. Therefore any time a lightning storm is near you’ll want to immediately unplug the 110 v cord, of course this is not possible when if the bike is unattended!
Uninterruptible Power Supply System
If for any reason you have to leave your bike plugged in and unattended, you can provide some additional protection with the use of a uninterruptible power supply system. While the battery back up feature will be minimal, it will still provide momentary inverter power during spikes in voltage as well as “open the circuit†in the event of a strike. Keep in mind, if a lighting spike gets in your bike, the damage could far exceed the cost of a UPS so its a good investment. I presently use these UPS units on not only my computers but also on all my TV’s, security camera, Wi-Fi System, alarm and even for my RV power.
Long Term Storage at high SOC
There is substantial documentation that shows it is much healthier to store lithium cells at 30-50% SOC then at full charge (80-100%). At present, the Zero battery management system does not offer any type of cell conditioning for long term storage.Therefore its up to the owner to monitor the SOC and take precautions when storing the bike for long periods of time.
Lithium Cells for Drone Use
Having used lithium cells since their inception in the RC Helicopter / Drone industry, we quickly found out that storing lithium cells at full charge would reduce the cells life and in some cases cause a chemical reaction to “Puff†the cells making them unusable. We remedied this problem when we discovered that cells stored at 40-50% had better health so modelers began discharging their packs to 40-50% after a flight project.
This is a typical drone lithium pack with the battery management module mounted atop the cell.
(http://www.com-pany.com/zero/bat.jpg)
As our drones evolved, we designed a high tech battery management for drones to balance and control charging of the cells. This BMS system was eventually mounted on each lithium battery pack, so when charging there was no extra connections to be made other than the charger itself since each battery had its own BMS.
Self Discharging Circuitry for Lithium Storage
A few years ago, we incorporated a new feature into the BMS which protects the cells during storage. This involves a user programmable routine, where we program a period time in days for the BMS to begin a “Self-Discharge†routine which automatically discharges the cells slowly to 40-50% SOC. Since most drone owners have many packs, this was a major advantage since they longer had to be concerned about managing each pack individually between uses.
While not mandatory, a system such as this could easily be adapted to the Zero’s BMS or even a separate aftermarket device could be offered. This discharge module would be powered by the bikes own pack and equipped with a resistive feature to discharge the pack to 50%. This would be helpful option for Zero owners since they would no longer have to be concerned during storage, the owner would just charge the battery to 100% and park the bike.
Since we don’t have this feature on the Zero, an easy work around would be to fully charge the bike, then ride it at moderate speeds to bring the SOC to around 50 percent. The bike could then just parked unplugged. At 50% SOC there is ample reserve to make up for the very minor loss which occur during storage with no concern of battery health. When Spring comes around, charge her up and your good to go.
IRIS Power Management System
I would like to share my Lowe’s Iris Wi-Fi alarm system and power management with you guys - Iris allows me to turn outlets on and off in my garage which power my electric vehicles chargers. I generally always keep my chargers plugged into the vehicles. When I need to charge or shut down a charger, instead of going out to the garage, I just open the Iris app on my phone to control the 110 volt outlets.
This is the 110 volt Wi-Fi controlled plug module - just plug your Zero in and your charging is controlled from an App on your phone.
(http://www.com-pany.com/zero/iris2.jpg)
Iris could be great for those owners who park their bike in a detached garage to control their charging. My camper is located in another building and its nice not having to track up there in cold weather, snow or rain to power or unpower the RV. I also have an electric heater in the RV which I turn on when the temperature gets below freezing, all done with ease sitting on my couch. Of course you could be in another state and control or top off your charging if you wish.
(http://www.com-pany.com/zero/iris.jpg)
Another nice feature of the Iris system it shows on the app how many watts its drawing at any given time. It also keeps track per session, once you enter your KW cost, it calculates exactly how much it cost to charge your car or bike on that session, weekly, monthly or yearly. What can I say, I love toys!
Zero’s Battery Warranty
In closing, I’m sure most owners would question why Zero would recommend leaving the bike plugged in and at full charge knowing it was not in the best interest of the battery. The answer is simple; the lost health of the cells being stored at full charge will not be a factor in their warranty period. Also since Zero can not control the charge level when the owner stores his bike, which may be depleted, or say 10-20%, their biggest fear is the cells self-discharging themselves to a critical level during storage and cell deterioration, so their simple remedy is to keep it plugged in.
Keep in mind Lithium cells only self-discharge at a rate of 2% to 3% per month, so if we stored the bike at 50% SOC, in 6 months it would only lose an average of 15% and therefore the pack would remain at a safe 35% SOC. Zero’s biggest fear is the cells self-discharging to a critical level and the need of replacement under warranty. With this in mind, they figure as long as the charger is plugged in and working everything will be in order. However, Zero's procedure fails to consider the owners safety risk and long term battery health as I outlined in this article.
Regards - Mike
(http://www.com-pany.com/zero/z99.jpg)
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All I can add is that the 2012 Zero ZF12 S that I gave my daughter has been plugged in 24/7 ever since January 2012 and still seems to be working just fine. If there has been any degradation of the battery pack, she hasn't noticed it (and neither have I when I ride the bike once and a while). The Zero keeps chugging along with only the occasional "glitch" when running wide open going uphill on the freeway. ???
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I'm sorry, but color me skeptical. I've been around long enough to know that just because it's on the internet, doesn't make it true. I have no idea who you are or what your credentials are for making the statements you made above, BUT Zero's engineers, who DEFINITELY have "skin in the game" say to leave it plugged in when it's not being ridden, they're the ones warrantying the battery and they're the ones who'd have to deal with any potential lawsuits from battery failures, explosions, fires, etc. so they're the ones I'm going to listen to on this particular topic.
I've also seen a representative from Farasis (the company that manufactures the batteries Zero uses) back Zero's claims right here in this forum. That's good enough for me.
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I read the Farasis post to agree with the OP on long term storage. And working in the battery world for the last 30+ years I also agree with all said.
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also, keep in mind, even though the Zero is plugged in, doesn't mean it's charging. The charger can be enabled and disabled both by algorithm upper set point, or by the Zero BMS.
Follow the manufacturer direction and let the BMS do its thing.
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We have had discussions about this before including a battery engineer form Farasis. My recollection is that he basically said if you don't want to hassle with it, leave it plugged in. If you don't mind tending to the bike while storing it, then leave it at a lower charge, but you are responsible if you mess up the batteries.
Sent from my iPad using Tapatalk
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The problem with leaving it plugged in is not that it is or isn't charging. The issue is that the battery is kept at full SoC all the time (which is worse than if kept at lower SoC) and that much of the bike's electronics are connected to the grid (which exposes them to potential voltage spikes that could damage them, not to mention faster aging of certain parts that happens when they are "on" all the time). The OP explained what the potential and real perils of these two are. Often the manufacturer's recommendations are targeted to the least common denominator in terms of users and use case scenarios. Often they can't take the risk and let the owners manage things even if it means they could do better, because they could also screw-up. The instructions in the manual are not always the best for the bike, especially beyond the warranty period. Remember that Zero is in for the money, and not necessarily for the best interest of the owners. How many of us will still have the same bike after 5 years, when the warranty is over? While their recommendations would certainly not result in premature failure within the warranty period, they are likely to increase the likelihood of failure or degradation of performance, especially past the warranty period. Up to each of us to decide what's best, of course, and weigh-in whether they want to put-up with the added effort and attention needed to manage the plugging and unplugging ;).
also, keep in mind, even though the Zero is plugged in, doesn't mean it's charging. The charger can be enabled and disabled both by algorithm upper set point, or by the Zero BMS.
Follow the manufacturer direction and let the BMS do its thing.
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The issue is that the battery is kept at full SoC all the time (which is worse than if kept at lower SoC)
It was stated on this forum that 100% SoC isn't actually 100% battery capacity. There is an upper limit at which the BMS will stop charging. This is intentional to prolong the battery's calendar life.
Lower SoC is indeed better but that incurs the risk of getting to too low a voltage which will irreversibly damage the battery.
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The issue is that the battery is kept at full SoC all the time (which is worse than if kept at lower SoC)
It was stated on this forum that 100% SoC isn't actually 100% battery capacity. There is an upper limit at which the BMS will stop charging. This is intentional to prolong the battery's calendar life.
Lower SoC is indeed better but that incurs the risk of getting to too low a voltage which will irreversibly damage the battery.
I have a bad experience that the battery completely depleted after a few months being unused, but plugged in.
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Yup. That's why I did not say "fully charged" as that would be more than full SoC :) And probably sufficiently low to not harm the bike too soon.
Given how slowly it self-discharges in my bike, I do not see a problem for it spending the winter unplugged. It's been sitting unused for over two months now and I don't see any self-discharge indicated on the dash or the app. I plan to ride it today for a few miles as the weather will be unseasonably warm and bring the SoC even further down to around 1/2 from the 87% indicated right now.
High self-discharge, especially with large cell imbalances when unused would indicate a defective or low-quality BMS, I would think. I don't think the BMS is active on our bikes when the bike is off and off the grid, so theoretically, it should not have the opportunity to mess-up the cell balance by just sitting inactive, but if a few of the modules have lower resistance it might lead to some cells being drained - and if it is just a cell or two, that won't show via the SoC and can go unnoticed, causing cell damage. That is why it is important to monitor the cell imbalance, which presumably is the difference between the most charged and the most discharged cell. So it is not enough to turn the bike on and look at the SoC, need to also check the cell balance with the app.
The issue is that the battery is kept at full SoC all the time (which is worse than if kept at lower SoC)
It was stated on this forum that 100% SoC isn't actually 100% battery capacity. There is an upper limit at which the BMS will stop charging. This is intentional to prolong the battery's calendar life.
Lower SoC is indeed better but that incurs the risk of getting to too low a voltage which will irreversibly damage the battery.
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I would like to point out that if you live somewhere like Scotts Valley, CA, and you ride your electric motorcycle every day, you want it to be fully charged before every ride to maximize your ability to go as far as you can. Keeping the charger plugged in all of the time will make sure that you are ready to go each day and do not have to do any additional charging before taking off in the morning. :)
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Yup, I'd probably be doing exactly that, for convenience, if I was riding it every day.
I would like to point out that if you live somewhere like Scotts Valley, CA, and you ride your electric motorcycle every day, you want it to be fully charged before every ride to maximize your ability to go as far as you can. Keeping the charger plugged in all of the time will make sure that you are ready to go each day and do not have to do any additional charging before taking off in the morning. :)
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I've been keeping my '17 SR at 100% charge when parked, but not always plugged in. I check the level periodically to see if has dropped and plug in as needed.
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Thanks for all the reply's guys - Regretfully, as I mentioned, the only safety valve to prevent over-charging and a fire is the BMS - as we all know these like any electronic circuity are known to fail. A good rule of thumb (if possible) is to only charge when home - never trust your lithium batteries.
Here's an article where two such charging incidents occurred and they removed 50 bikes from service.
(http://www.com-pany.com/zero/fire.jpg)
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I had heard there was a faulty plug and that this was NOT battery related.
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I'm sorry, but color me skeptical. I've been around long enough to know that just because it's on the internet, doesn't make it true. I have no idea who you are or what your credentials are for making the statements you made above, BUT Zero's engineers, who DEFINITELY have "skin in the game" say to leave it plugged in when it's not being ridden, they're the ones warrantying the battery and they're the ones who'd have to deal with any potential lawsuits from battery failures, explosions, fires, etc. so they're the ones I'm going to listen to on this particular topic.
I've also seen a representative from Farasis (the company that manufactures the batteries Zero uses) back Zero's claims right here in this forum. That's good enough for me.
JaimeC thanks for the reply, I fully understand you being skeptical.
Regarding your question of my credentials to dispute Zero or Farasis's charging recommendations, I have worked on a professional level with military and hobby lithium powered helicopters & drone aircraft since the early 90’s to include contracts for Martin Marietta Aerospace long before there was even a thought of Zero motorcycle.
Without being disrespectful to Zero and Farasis Company in any respect, they are “Dead Wrong†recommending their customers leave their lithium powered bikes on charge for up to months at a time un-attended. There is absolutely nothing to dispute, it is dangerous and not recommended. I explained in my original post their reasoning is to prevent warranty claims. In my years in the model industry, I have seen first hand many of my co-workers homes and business burnt to ground as a result of lithium cells.
Thanks
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One more reason not to keep them plugged-in when not necessary and to monitor them during charging if at all possible. Although, if the cable or plug was at fault, it would matter only during full-current charging, where it could get hot (which it probably would not during top-up/equalization due to the very low current then).
Heck, even Tesla caught on fire during charging in Europe last year (I have not followed on why exactly). Not to mention other non-vehicle electrical devices catching fire when unattended. Stuff happens, if we can minimize the chance for it, I'm all for that...
I had heard there was a faulty plug and that this was NOT battery related.
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Here is the quote from the Farasis engineer:
"So, to prolong your battery life, you can do the exact opposite. Store the bike in a cool place with a stable temperature at low SOC.
~20% or so is fine for S/DS (one BMS sipping on 3-5 cellboxes) or 30-40% for the FX modules (one BMS per cellbox)"
You have the OP with extensive experience with li-ion and myself with over 30 years of full time work with various battery chemistries and 8 years first hand experience with li-ion and all 3 of us agree on this point. Admittedly, the engineer did say that plugged in all the time would likely not kill the battery within the warranty period.
Can we end this debate now?
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The Farasis engineers storage statement below is not correct for long term storage:
"~20% or so is fine for S/DS (one BMS sipping on 3-5 cellboxes) or 30-40% for the FX modules"
The reason this is in error; the average self-discharge rate of lithium of 2% to 3% per month, so in 6 months the cells would most likely discharge around 15%. If we stored the bike as he recommended with only a 20% and lose 15% charge, you could easily end up with a critical low SOC which could destroy the cells.
To be safe, reduce the charge to 50% this way if we loss 15% from self-discharge, the pack would remain at a safe 35% SOC.
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The Farasis engineers storage statement below is not correct for long term storage:
"~20% or so is fine for S/DS (one BMS sipping on 3-5 cellboxes) or 30-40% for the FX modules"
The reason this is in error; the average self-discharge rate of lithium of 2% to 3% per month, so in 6 months the cells would most likely discharge around 15%. If we stored the bike as he recommended with only a 20% and lose 15% charge, you could easily end up with a critical low SOC which could destroy the cells.
To be safe, reduce the charge to 50% this way if we loss 15% from self-discharge, the pack would remain at a safe 35% SOC.
From memory this was the ideal level of charge to prolong battery life, but needs constant monitoring. Not a recommendation to set and forget.
The farisis engineer also stated that batteries at full charge in a hot place is bad. Therefor if in winter the affect is much less. The heat speeds up the chemical degridation.
But in the worst case scenario it would still take over 5 years to damage the pack.
Some common sense is needed, if you live in a hot climate then you should do the extra effort to lower SOC for storage, if in a cold climate its not going to make much difference.
The engineer also stated that farisis cells have a more robust chemistry than the lipo cells used in RC models
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@Low On Cash, does the Iris app alert you if there's an anomaly happening? This thread has me fearful of the possibilities. I have my bike in a basement garage and I assume with a battery the size of the SR's it could start a raging fire that could engulf the house in no time flat. So a heads up that something is wrong could be a life saver. I don't leave my bike plugged in when we go out of town but, I do leave it plugged in most other times.
Sent from my iPhone using Tapatalk
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@Low On Cash, does the Iris app alert you if there's an anomaly happening? This thread has me fearful of the possibilities. I have my bike in a basement garage and I assume with a battery the size of the SR's it could start a raging fire that could engulf the house in no time flat. So a heads up that something is wrong could be a life saver. I don't leave my bike plugged in when we go out of town but, I do leave it plugged in most other times.
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Thanks for the reply - to my knowledge the Bluetooth App does not have any provisions to alert the owner, even if it did, being bluetooth instead of Wi-Fi the range would be very limited.
I highly recommended the Iris system since it allows you the ability to shut off or power the Zero from any location by your Iphone App.
Of course I would not recommend you leave the bike plugged in for storage reasons, but if you do charge in a remote area install the best smoke / Fire detector you can find so you'll hopefully have some warning.
Thanks
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@Low On Cash, does the Iris app alert you if there's an anomaly happening? This thread has me fearful of the possibilities. I have my bike in a basement garage and I assume with a battery the size of the SR's it could start a raging fire that could engulf the house in no time flat. So a heads up that something is wrong could be a life saver. I don't leave my bike plugged in when we go out of town but, I do leave it plugged in most other times.
Sent from my iPhone using Tapatalk
If a Zero battery pack or charger has ever caught on fire, I sure haven't heard about it during the past 5 years that I have been visiting this forum. And like I have said previously, my daughter has kept her 2012S plugged in all of the time, even during thunderstorms and flooding in her garage (just because she doesn't think about unplugging stuff (or recharging batteries, for that matter) and has yet to have an issue. While I agree with you that unplugging your bike while you are away from your home for any length of time is a good idea, and something that I do, I doubt you should be worried about hover-board or Note 7 disasters. ;)
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At present - every Zero owner is risking the safety of their family and home on the integrity of the battery management circuit which has already shown it abilities to fail on numerous occasions. I'm not trying to panic anyone into changing their charging habits - but only make them aware of the potential dangers of un-attended charging. Keep in mind, the Zero is not a hover board, phone or cigarette, if a 13kw pack goes up, more than likely it will take the structure with it.
I feel for safety reasons, Zero should immediately revise their recommendations regarding long-term Un-Attended battery storage.
As an option - Zero could easily design and install an “Over Charge Prevention" feature in their charging circuit so in the unlikely event the processor become erratic, fails or locks up, a "normally open" relay would break the connection from the charger to the pack to prevent an over-charge state of the cells and a subsequent fire potential. Another protection feature could be a redundant SOC monitoring circuit to where if the battery reaches 100% SOC a normally open relay would open it from the charging circuit.
Since there is a major liability for manufactures, my work in the drone industry entails rigid safety procedures concerning safe operation and charging of lithium, It took years of mistakes and many home and business fires before the model industry offered a safe product. Our policy is simple; “No Un-Attended Charging†period. We urge modelers to be present during charging.
Since I consult for many manufactures and forced to deal with different manufactures of lithium packs, at our work place we have "safe areas" for the cells. Even at my home for my own models and electric bicycles, I installed a steel "Safe Room" in my garage for storage and charging of lithium cells. I mention this not for motorcycles, but to show there should always be concern for lithium cells.
(http://www.com-pany.com/zero/safe.jpg)
(http://www.com-pany.com/zero/safe1.jpg)
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The evidence cited here is really mixed up - the HK police bike that caught fire was a 2012 model (as visible in the photo) using EIG cylindrical cells, not Farasis cells.
Ref. http://zeromanual.com/index.php/Unofficial_Service_Manual#Cell_Arrangement (http://zeromanual.com/index.php/Unofficial_Service_Manual#Cell_Arrangement)
The bulk of Farasis' market (seems like 80% from past references) lies in the industrial sector, for forklifts and small trucks in warehouse settings, and I'd bet that they operate with similar recommendations even if the duty cycle is more demanding.
Honestly, Low On Cash's pronouncements have been self-aggrandizing and arrogant, and should be regarded with skepticism. In this particular case, taking the argument at face value reveals an inadequate comparison and an example that they haven't fully understood or are using to mislead.
I don't care how right Low on Cash is about the drone situation, and do not care to convince him of anything, but wish to make sure that public visitors read this thread with a serious grain of salt and to make clear that we don't just buy a sketchy argument trotted out by someone convinced of their own credentials and downplaying others'.
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Thanks, Brian. Since I have it IN writing from the manufacturer in a legally binding document (the Owner's Manual) I am going to leave my Zero plugged in whenever it is not being ridden. As I originally stated, Zero (and the Farasis engineers) have skin in the game, and if something should fail, THEY are the ones who will pay the price in lawsuits. I am well aware that neither company would make their recommendations without EXHAUSTIVE research beforehand. They can't afford to be wrong.
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Zero could easily design and install an “Over Charge Prevention" feature in their charging circuit so in the unlikely event the processor become erratic, fails or locks up...
This is a standard feature of microcontroller programming called a watchdog. It's very unlikely that this isn't already in place.
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This is a standard feature of microcontroller programming called a watchdog. It's very unlikely that this isn't already in place.
Of course it is. Anybody with the slightest clue about electronics design would know that.
People have REALLY got to stop feeding this ignorant troll.
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I don't think it's necessary to insult the OP. He has his opinion and he's welcome to it. I just think one needs to give it some good, hard, critical thought before jumping to conclusions, that's all.
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People have REALLY got to stop feeding this ignorant troll.
The problem is that he occasionally come up with something interesting and informative. It'd be nice to encourage that rather than completely writing someone off.
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Thanks for the reply’s guys - I would like to remind everyone my original post and my following remarks are for safety reasons only and to help raise awareness of the potential dangers of “Un-Attended Charging†of lithium cells.
Regretfully, some reply’s such as Brian’s “Goofy†comments on this thread are only in place to divert attention from the subject matter because I corrected his mistakes regarding the Zero’s regen and Bluetooth functions. Rather than him learn from his mistakes, he has chosen to follow me around in a futile attempt to dis-credit important safety information such as this one concerning the dangers of charging of lithium cells.
In this same thread Brian is “Once Again†wrong in his mentioning the early “Police Bikes†which caught fire were cylinder cells - as if that would make any difference at all, cylinder cells exhibit the same fire dangers from over charging as pouch cells.
Brian was wrong again when he mentioned newer pouch cells are safer, when in fact they are more dangerous to a neighboring overheated cell than a cylinder cells. Unlike a cylinder cell which has a hard case and very little contact area to the neighboring cell, a pouch cell has close proximity to the other cells which allows easy convection heating of the neighboring cells and increased possibility of chain-reaction overheating.
Getting back to the topic - please understand, I’m not implying that anyone has to follow my procedures, I’m only attempting to bring attention to Zero’s incorrect storage recommendations and Farisis's flawed storage battery percentage comments.
Without being redundant - the Zero’s battery management system has been prone to failure - numerous failures are well documented on this same forum and on Facebook. The real question is; why would anyone risk their home on the integrity of this BMS that has already show failure? Facts are Facts - if the BMS does not conclude a charge as a result of a frozen processor or lightning spike; “It Will Result In a Fire†Period!
Regretfully, a few users have challenged the validity of my threads. I'm not trying to be self-serving here but my line of work requires high levels of mechanical and electronic knowledge and therefore I have a solid background on lithium power vehicles. To my credentials I designed built the worlds first military and aerial drone in 1976, afterwards I consulted for companies around the world at a professional level on military & civilian projects with lithium powered vehicles, long before Zero was even a thought! If anyone needs proof, I invite you too visit my personal site at: www.rotory.com (http://www.rotory.com)
In closing, I have included an image of my close Dave's home totally engulfed in flames. He too is in the modeling industry and recently lost everything he owned from a lithium fire which started in his garage which then consumed his home.
I again urge all Zero owners to take what ever precautions you can when charging your bike and disregard any comments with regard to leaving your bike on charge for days, weeks and months, unattended. There is nothing to debate - lithium cells are dangerous.
Regards - Mike
(http://www.com-pany.com/zero/fire2.jpg)
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Well, I don't feel so bad now about not having a garage to park my bike in.
2015 FX ZF6.5 👹 DoD #2160,6
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I just want to say something about the argument that Zero and Farazis "have skin in the game". Without defining what their interests are, it is not at all a good argument to support that we should follow their recommendations (or not). Here's what most manufacturers' "skin in the game" is - make as much money with as little investment as possible. Not all are like this, but most. That's how capitalist business works. Simple as that. If that means the products they sell will barely survive the warranty period or fail shortly after it, they've still achieved their objective.
All some of us are saying here is that, while the manufacturer's recommendations will most likely be fine to follow, there is a very solid argument to be made that one can do better than that. Personal feelings aside, the factual arguments presented here by many folks are quite good. The "faith-based" statements without factual substantiation to "just follow the book" don't help one reach a better logical discussion, other than to inform others of how you feel, perhaps...
No offense meant to those who follow "The Book" (in capital letters, whichever book that might be, that's their choice), but I think we should be a bit more analytical about the product manual ;). There are several recent posts on this very form about several Zeros that have not maintained their charge properly when constantly plugged-in. Worse, their cell balance has been messed-up. Answer from Zero has been "a firmware bug". Would these same bikes have lost charge/balance if kept unplugged? Most likely not, since the BMS would have been inactive and the firmware would not matter. So, when presented with clear evidence and solid analytical arguments for one thing, insisting on doing the opposite seems a bit strange to me. And insulting those who dare say otherwise is plain inappropriate...
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I should also mention another piece of evidence, from another manufacturer, Vectrix. It is a well-documented fact that certain model chargers had a software bug that resulted in the charger being stuck in full power indefinitely, regardless of SoC. That, as you expect, kills the battery. Luckily, the bikes with those types of chargers had NiMh batteries, so no fires were reported as far as I know. But many costly battery replacements (under and outside of warranty). I have personally experienced that failure mode several times on my own Vectrix. That's despite the fact the charger has 3 "fail-safe" checks to avoid precisely that - SoC, temperature, and time. Yet, since those checks are all software-based, that bug caused the charger to keep charging well past the max SoC and only shut-off at the time limit, which is way past overcharging... Who can guarantee that a big like that won't happen with the next firmware update on a Zero? Bugs like these are hard to catch in production because they do not happen every time, they might happen once in a 300 charge cycles, not happen at all, or happen 2x in a row...
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Manufacturers ALSO want to avoid costly lawsuits, class action suits and damaged reputations. There is more to "Skin in the Game" than simple profit margin, you know.
By the way, the battery is warranted for five years, even though the rest of the bike is only warranted for two. Based on what I've seen, the cost of replacing the monolith (parts and labor) appear to be prohibitive enough that most people would likely just want to get a new bike anyway. And considering how much these bikes improve year by year, that would be the wise thing to do anyway. Look how far they've come in ten years! Who know where they'll be in another five. :)
BTW, I know my battery is "only" warranted for five years/100,000 miles BUT there is also no way with the way that I ride the bike that I'll be putting 20,000 miles a year on it so it may as well be five year/unlimited miles (like the 2017 models). I picked up my bike in April of 2016 and just now scheduled my 8,000 mile service.
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And that most of us will never even come close to the warranty period for the battery on our bikes is a argument for not worrying about it too much and just keep them plugged in. Let's talk again in 5 years and see if folks are complaining of battery degradation then. There is no data right now, other than for early bikes that exactly that was happening - the batteries on '12 bikes were recalled due to lost capacity. Why? Bad cells? Bad battery management? Who knows... If I can do something to minimize the chance of that, which does not inconvenience me, and which decreases the chance of catastrophic failure, I'm inclined to do it. Might or might not be the best way for others.
Personally, I think the Zero batteries and BMS are fairly safe and I trust them enough to charge them at home :) My argument to myself, which I share here not as a recommendation but as food for thought (and entirely to the discretion of the reader) is to not use them in ways that increase the chance of failure, even if the manual says otherwise.
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Actually, that's still profit margin. If there were no regulations and laws, you think they'd care much? Seatbelts, tobacco, fuel economy/pollution... Very few out there have my benefit above theirs, most are working for their own interest first and foremost.
Manufacturers ALSO want to avoid costly lawsuits, class action suits and damaged reputations. There is more to "Skin in the Game" than simple profit margin, you know.
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As I have mentioned before, my daughter's 2012 S, which has just turned 5 years old last week, has been plugged in continuously all of that time and has had no obvious battery degradation so far. :) It still runs as well and as far as it did when it was new. :) But I will admit that it has been exposed to very little riding in the rain (and hasn't been washed in years) and almost never gets stressed by its rider. It is difficult to generalize about any mechanical or electrical product. Some work as intended and some don't. There are likely a myriad of reasons why this is. ??? I go with the manufacturer's recommendations because I figure that they know more about their product than I do. ;)
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No offense meant to those who follow "The Book" (in capital letters, whichever book that might be, that's their choice), but I think we should be a bit more analytical about the product manual ;). There are several recent posts on this very form about several Zeros that have not maintained their charge properly when constantly plugged-in. Worse, their cell balance has been messed-up. Answer from Zero has been "a firmware bug". Would these same bikes have lost charge/balance if kept unplugged? Most likely not, since the BMS would have been inactive and the firmware would not matter. So, when presented with clear evidence and solid analytical arguments for one thing, insisting on doing the opposite seems a bit strange to me. And insulting those who dare say otherwise is plain inappropriate...
IIRC the BMS is always on.
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Good point. I actually do not know if it is always on and what that actually means. As far as I know, the BMS does stay on for a bit after the bike is turned on - I can see the status lights under the front battery cover on initially, but then they turn off. It does wake-up from the two buttons there. But what is it doing otherwise when the bike is off I have no idea. What I'm pretty sure is that the BMS can only do top balance whole charging, so if the bike is off and unplugged, it probably won't do anything to prevent cell discharge or imbalance. What I am more interested in is if it is truly off or almost off, e.g., it is not measuring the cells (or otherwise potentially screwing with their balance or draining the battery).
As for the firmware not mattering, I meant that the bike does wake-up periodically to top-up the charge, so if it is unplugged, it won't be doing that, so whatever it was doing when plugged, I assumed would not be happening when unplugged (perhaps incorrectly, as the BMS might indeed be "on" even if the charger, controller, etc. are "off").
[quote sauthor=Kocho link=topic=6583.msg52403#msg52403 date=1485958630]
...since the BMS would have been inactive and the firmware would not matter.
IIRC the BMS is always on.
[/quote]
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...
In closing, I have included an image of my close Dave's home totally engulfed in flames. He too is in the modeling industry and recently lost everything he owned from a lithium fire which started in his garage which then consumed his home.
I again urge all Zero owners to take what ever precautions you can when charging your bike and disregard any comments with regard to leaving your bike on charge for days, weeks and months, unattended. There is nothing to debate - lithium cells are dangerous.
Regards - Mike
To be fair, there are many, many different types of lithium batteries and they are not all created equally. You mentioned your friend Dave is in the modeling industry. In my personal experience, I select batteries for my model aircraft based on energy capacity, discharge rate, and weight. They have no BMS, are prone to physical damage, intolerant of over charge or discharge, temperature sensitive, etc., and there is no way I would leave them charging unattended. Every bit of caution you described is completely appropriate when dealing with this type of battery.
At times, manufactures have made some poor selections in battery chemistry trying to squeeze more energy into less space and weight. Dell had laptop batteries recalled, Samsung Galaxy 7 phones, Boeing 787 Dreamliners are some notorious examples. The manufactures have taken steps to correct these issues and they are not the same type of cells that are used by Zero.
A123 popularized a type of cylindrical Li-Fe cells which are significantly less volatile than the type typically used in model aircraft because of weight, cost, and slower recharge rates. A123 batteries are what my car (not a model) uses, and my motorcycle utilizes Farasis NMC batteries. My cell phone uses yet another type of Lithium ion battery, as does my camera, laptop, tablet, rechargeable headset, video cameras, etc. Additionally, all of these have some type of BMS and I sleep quite well while all of these get recharged overnight.
Some level of caution is warranted with any battery, but I don't think it is reasonable to lump all lithium batteries into the same category as the ones commonly used for model aircraft. I consider most of the lithium batteries I use to be far safer than a regular lead acid battery and far safer than liquid fuels such as gasoline.
Stay safe,
Chocula
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While every EV fire and Telsa crash tries to make the newsfeeds, the model airplane with conventional fuel that burns a few people misses top of Breitbart and is left well below the fold.
http://www.theledger.com/news/20150306/florida-jets-event-rc-plane-crash-injures-pair-of-men-at-airport (http://www.theledger.com/news/20150306/florida-jets-event-rc-plane-crash-injures-pair-of-men-at-airport)
http://www.local10.com/news/explosion-leaves-large-hole-in-roof-of-margate-home (http://www.local10.com/news/explosion-leaves-large-hole-in-roof-of-margate-home)
(and many more)
RC planes have been catching fire and occasionally burning down houses for ages. I got my FCC license to fly... KBSG5826 "R/C Radio Service Station License" original paperwork dated 5/10/1981. It is just accepted that RC plane fuel burns... you just have to ask:
https://www.rcgroups.com/forums/showthread.php?1987095-Do-fuel-RC-planes-explode/page2 (https://www.rcgroups.com/forums/showthread.php?1987095-Do-fuel-RC-planes-explode/page2)
Cars also burn...
http://www.nfpa.org/public-education/by-topic/property-type-and-vehicles/vehicles (http://www.nfpa.org/public-education/by-topic/property-type-and-vehicles/vehicles)
http://www.nfpa.org/news-and-research/fire-statistics-and-reports/fire-statistics/vehicle-fires/vehicle-fire-trends-and-patterns (http://www.nfpa.org/news-and-research/fire-statistics-and-reports/fire-statistics/vehicle-fires/vehicle-fire-trends-and-patterns)
Facts and Figures
- Automobile fires were involved in 10% of reported U.S. fires, 6% of U.S. fire deaths.
- On average, 17 automobile fires were reported per hour. These fires killed an average of four people every week.
- Mechanical or electrical failures or malfunctions were factors in roughly two-thirds of the automobile fires.
- Collisions and overturns were factors in only 4% of highway vehicle fires, but these incidents accounted for three of every five (60%) automobile fire deaths.
- Only 2% of automobile fires began in fuel tanks or fuel lines, but these incidents caused 15% of the automobile fire deaths.
According to the U.S Federal Highway Administration data, roughly 2,980 billion miles were driven, on average, per year on U.S. roads during this period. Roughly 90 highway vehicle fires and 0.15 highway vehicle fire deaths were reported per billion miles driven.
Tesla passed a billion fleet miles way back in October 2014, so normal stats would be 90 Tesla fires for that billion miles, but they come up far far short.
Anecdotal is fine for conversation - but to make decisions use aggregate risk.
Propane tanks? Those go in the shed.
Oxyacetylene Torch? That goes in the shed.
Lawn chemicals? Shed.
My Zero - charges in the garage, along side the cars I also park there, attached to the house I sleep in.
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Thanks for the reply's guys!
I'm looking at battery storage from a "Safety" standpoint. Having worked with lithium cells as a profession in my trade, I have seen them fail on too many occasions. It's important to note that all lithium cells offer a potential fire risk. My original post and fallowing messages clearly prove the Zero's battery management system is prone to failure and continues to fail on a daily basis. This combined with the fact the BMS has no redundant back-up system to terminate a charge should the BMS fail, leaves the Zero in a state that overcharging can and will result in a fire - this has already happened to these bikes in the past when left on charge un-attended.
Most important - there is no basis to leave the Zero on charge unattended when the bike can just as easily be stored with 50-70% charge and have the same exact security to prevent the battery from reaching critical low conditions. With this in mind - why would anyone risk their family and home on the integrity of a low cost BMS that is know to fail.
Regards - Mike
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Once again, some solid advice is wrapped in an incredible self-regard and overstated certainty about outcomes with incomplete evidence. No amount of professional background justifies the kind of rhetoric used here, and it detracts heavily from the message. I would rather not see advice like that at all, than see it presented here the way it has. There are plenty of competent engineers in this world; those who practice their profession with insults can be done without.
Here's the conservative safety advice for unattended storage (defined as not checking the vehicle more than once a week, say):
- Leave the bike unplugged unless there is a below-freezing temperature concern about battery storage.
- Leave the state of charge at 50-70%.
- Visit the bike monthly and check on the state of charge; if below 40%, say, initiate a charge to a high end of the range; if there's cell imbalance, ensure cel balance is restored and then discharge the battery to 70-80%, say, before leaving it unplugged and unattended for another month.
I am unconvinced that a BMS failure would be consistent with the charger operating; the onboard charger does not get a connection to the battery without positive BMS response based on what I've learned from engineers, and the contactor would not close without that direction and does not have a fail-closed possibility in the last few years of models. I may have misheard or misunderstood, but I've not heard a single piece of evidence to suggest a failure mode like this, and good engineering fail-safe practice is consistent with this.
I would be more persuaded by a schematic breakdown that illustrates possible system interactions than I am by comparisons to drone aircraft systems that don't hold up when I think of everything I've heard and documented by good engineers on this forum and elsewhere.
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At any given moment during the work-week there will be around 10 bikes outside of Zero HQ, all plugged in. Seeing as they practice what they preach, I'll continue to go with their advice.
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Brian (quote) Visit the bike monthly and check on the state of charge; if below 40%, say, initiate a charge to a high end of the range; if there's cell imbalance, ensure cel balance is restored and then discharge the battery to 70-80%, say, before leaving it unplugged and unattended for another month.
This is where I get frustrated with the contradiction of "leave it plugged in for 72 hours to ensure the cells balance" and "100% SOC can hurt the batteries in the long term", with both statements being true but regarding different issues.
First how do I know if they are unbalanced?
Next could it ever be set up to balance at a set SOC like 70% and shut off charging from the app or will a BMS only balance as full SOC cells bleed off a little voltage at a time and let the others catch up?
How long would it take to be at 100% SOC to start to really stress out the cells? A few days, a week, a few months?
I realize this is not a critical issue just like changing the oil in a car at 3500 miles won't cause a seized engine but some good rules of thumb would be great to start to ingrain into new EV owners heads.
Thanks as always for every ones input and knowledge on these matters.
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Visit the bike monthly and check on the state of charge; if below 40%, say, initiate a charge to a high end of the range; if there's cell imbalance, ensure cel balance is restored and then discharge the battery to 70-80%, say, before leaving it unplugged and unattended for another month.
This is where I get frustrated with the contradiction of "leave it plugged in for 72 hours to ensure the cells balance" and "100% SOC can hurt the batteries in the long term", with both statements being true but regarding different issues.
72 hours is longer than I know about - 24-48 seems like it usually works. In any case, 72 hours is not long term compared to leaving the bike unattended for a month or more.
First how do I know if they are unbalanced?
Use the mobile app's battery screen or a DigiNow dongle to extract the data.
Next could it ever be set up to balance at a set SOC like 70% and shut off charging from the app or will a BMS only balance as full SOC cells bleed off a little voltage at a time and let the others catch up?
Right now, you can't get the BMS to rebalance cells without using the onboard charger, and usually to use it at/to 100% SoC.
While I hope that Zero is not so fickle as to rely on us jabbering on the forum anxiously when designing BMS features, I do hope they've already considered this sort of thing for new firmware updates, if the leaks are to be believed, maybe by using the app to direct the bike to use a "storage mode".
Maybe you could game the current software by unplugging the bike at a low level of charge, waiting a while, then plugging it back in, but someone would have to really monitor the balancing by the app to see whether it would even respond to such trickery.
How long would it take to be at 100% SOC to start to really stress out the cells? A few days, a week, a few months?
See, this is where some very clear language (that we lack) makes a big difference. It seems that the experts are talking about battery-lifetime-level factors, and that the risk is chemical around dendrite formation around the lithium anodes, and my understanding is that this process is fine if it's short term, because regular usage sort of clears it up, whereas longer periods eventually accumulates in a more permanent sense.
What the parameters are of those curves are, I'm not entirely clear on aside from some engineering summaries published online.
We still have the captured advice of a Farasis engineer about the matter, which generally rounded it to "more than a few days" and "Zero seems to have factored in plugging it in all the time into their battery lifetime estimates":
http://zeromanual.com/index.php/Unofficial_Service_Manual#Battery_Storage_and_Capacity_with_Age (http://zeromanual.com/index.php/Unofficial_Service_Manual#Battery_Storage_and_Capacity_with_Age)
I tried to distill it further here, partly based on concerns raised in this thread, mediated by the engineering background put into the battery article above:
http://zeromanual.com/index.php/Usage#Storage (http://zeromanual.com/index.php/Usage#Storage)
I realize this is not a critical issue just like changing the oil in a car at 3500 miles won't cause a seized engine but some good rules of thumb would be great to start to ingrain into new EV owners heads.
Thanks as always for every ones input and knowledge on these matters.
I'm just trying to make sense of everything I've heard like you are. In this case, I've become local to some relevant people and aggressively curious enough to keep prodding them until I get a bunch of answers that seem consistent internally and externally.
I think what we're talking about has a bit of a risk curve that's worth exploring, but getting worked up about and dramatizing the negatives is unhealthy. I'm hopeful that with a basic maintenance discipline and the app both coaching the user and customizing the software mode, we could get 100k miles out of a battery with minimal risk. That's why I take even unhealthy discussions as lessons on what to put on the wiki.
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Thanks for breaking down my questions Brian. I looked up the 2013 Zero manual and found two bits of information on this from Zero. One was where I got the 72 hour advice but it is only for an "unbalance error". It's in section 6.6 here.
http://media.zeromotorcycles.com/resources/owners-manuals/2013/2013-Zero-Owners-Manual-S-DS.pdf#page=99&zoom=auto,478,100 (http://media.zeromotorcycles.com/resources/owners-manuals/2013/2013-Zero-Owners-Manual-S-DS.pdf#page=99&zoom=auto,478,100)
But the section that covers this best regarding over charging is:
During an ordinary charging cycle, when the cells are
balanced, the charger (not t
he BMS) senses that the
power pack is full and terminat
es the charging cycle with a
“green light.†The BMS does have a redundant back-up
mechanism to prevent overcharging of the power pack. If
the charger fails to terminat
e a charging-cycle when the
power pack is full, the BMS will terminate charging itself to
prevent damage.
So the BMS backs up the charger not the other way around so if there is a third safety back up would be the only question at this point. Either way before my battery replacement recall mine showed errors and kept any real problems from happening so I'm ok with it so far.
I'm posting this just to get info out there as I am curious as well to know as much about these bikes as I can (without getting an EE degree) thanks again for all the posts and seeking positive approaches to issues big and small.
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All of us plug in our Zero's and leave the room, the whole basis for my cautions is "Long term Storage" and leaving the bike on charge for months which has to be one of the most ridiculous recommendations I've seen yet from a manufacture.
Take my word, Zero is 100% incorrect on this one and don't be shocked to see a revision in future manuals since they have been notified form me concerning this dangerous practice.
Please do exactly what you want to do. If you're ok with risking your home to a $19.00 battery management board then fine, its your home and family. No matter how you guys attempt to twist the facts around, any BMS that does not terminate its charge on a lithium battery will result fire.
Period. . . . .
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Mike I'm not against you. I don't think anyone is twisting facts. ANY safety feature on any product CAN fail with very bad results. There is a fire risk with anything flammable near a heat source. Zero's CAN catch fire but a lot of things have to fail first. I'm not saying it can never happen but I don't believe it is at all likely in an undamaged state. I feel it's less risky than a gas leak from an ICE bike or car or a natural gas leak or cooking fire or fireplace fire that have no real means of stopping those fires.
I never followed the "leave it plugged in all the time" suggestion myself because of the storms here in GA, I didn't want the chargers fried so I plug it in at night and unplug it in the morning.
I think it is in the manual from the 2010 and 2011 bikes which would canabelize battery cells as they tried to keep a certain SOC killing the bike. (look up EV Jedi on You Tube) Which at that time was the most pressing problem so the "just leave it plugged in" came to be. I think it could very well be removed soon and I hope "we" (non battery experts like myself) get a bit more of "why" things need to be done and not just a "rule" to follow.
Frankly what got me more was no mention of 100% SOC stressing a battery. I never knew that at all until I saw it on here regarding all Li-on batteries. I assumed a full battery was a happy battery. Then I understood the "voltage is pressure" concept and now see how that would be stressful.
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It's so clearly not a $19 BMS board, more like several hundred dollars just from a casual BOM reverse engineering and asking around, and the way charging protections are arranged (see above about how the contactor is activated and how it fails, which has been repeatedly verified with lots of charger testing by myself and others) flatly contradicts your assertions.
The only BMS deficiency is lacking a long-term storage mode, which can be compensated for by the recommendations we've compiled until Zero figures out what they'd like to do about this.
This argument smells more like defamation than professional advice given in good faith, particularly since you claim to be a professional but haven't bothered to square any of your claims about Zero's systems with others' knowledge here.
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The big disconnect for me here is trying to compare a $14,000 motorcycle to a $1,000 toy aircraft...
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The big disconnect for me here is trying to compare a $14,000 motorcycle to a $1,000 toy aircraft...
Jamie thanks for your reply, however it only shows your lack of understanding of the scope in which I work.
The Remote Piloted Vehicles RPV military drones both fixed wing and Rotory in which I design and work on for defense contractors such as Martin Merietta Aerospace and others are priced from $250,000 to well over a million. I hope this clarifies your negative remark on such an important safety matter.
Regards - Mike
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The big disconnect for me here is trying to compare a $14,000 motorcycle to a $1,000 toy aircraft...
Jamie thanks for your reply, however it only shows your lack of understanding of the scope in which I work.
The Remote Piloted Vehicles RPV military drones both fixed wing and Rotory in which I design and work on for defense contractors such as Martin Merietta Aerospace and others are priced from $250,000 to well over a million. I hope this clarifies your negative remark on such an important safety matter.
Regards - Mike
Then you must understand the difference between a battery pack, BMS and charger designed to charge each cell to 4.4V or even 4.5V and one that only charges to 4.15V per cell. If you have the experience you claim you would know by doing simple math that Zero only charges to 4.15V per cell and you would know that this is a much safer voltage than 4.4V for lithium chemistries. That difference is the reason the Zero pack can be 'fully charged' and still provide at least 80% original capacity after hundreds of thousands of miles (1800 cycles or more) whereas your cell phone, hobby drone or overpriced military drone only last 400-800 cycles.
The Zero charger would have to charge the bike to over 120V before you would be in the danger zone and the stock charger isn't capable of going that high.
Sent from my Nexus 6P using Tapatalk
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The big disconnect for me here is trying to compare a $14,000 motorcycle to a $1,000 toy aircraft...
Jamie thanks for your reply, however it only shows your lack of understanding of the scope in which I work.
The Remote Piloted Vehicles RPV military drones both fixed wing and Rotory in which I design and work on for defense contractors such as Martin Merietta Aerospace and others are priced from $250,000 to well over a million. I hope this clarifies your negative remark on such an important safety matter.
Regards - Mike
Then you must understand the difference between a battery pack, BMS and charger designed to charge each cell to 4.4V or even 4.5V and one that only charges to 4.15V per cell. If you have the experience you claim you would know by doing simple math that Zero only charges to 4.15V per cell and you would know that this is a much safer voltage than 4.4V for lithium chemistries. That difference is the reason the Zero pack can be 'fully charged' and still provide at least 80% original capacity after hundreds of thousands of miles (1800 cycles or more) whereas your cell phone, hobby drone or overpriced military drone only last 400-800 cycles.
The Zero charger would have to charge the bike to over 120V before you would be in the danger zone and the stock charger isn't capable of going that high.
Sent from my Nexus 6P using Tapatalk
Thanks for the reply - all your assumptions are correct only if the BMS is operating as intended. Evidently most of you guys replying here are not reading the original post or my following reply's. My comments have 0% to do with the Zero's charging protocol and 100% to do only with the unsafe recommendations from Zero regarding un-attended charging for months and months at a time.
Facts are Facts; In the event of a BMS failure to terminate a charge or a simple lightning spike that freezes the processor it "Will Result In A Fire" there is no question about it.
Anyone who knows anything about lithium cells would question why Zero would recommend leaving the bike plugged in and at full charge knowing it was not in the best interest of the batteries health. The answer is simple; the lost health of the cells being stored at full charge will not be a factor in Zero's warranty period.
Zero cannot control the charge level when the owner stores his bike, which may be depleted, or say at 10-20%, so their biggest fear is the cells self-discharging themselves to a critical level during storage and cell deterioration, so their simple remedy is to keep it plugged in.
My recommendation of storage is 100% safe - Lithium cells only self-discharge at a rate of 2% to 3% per month, so if we stored the bike at 50% SOC, in 6 months it would only lose an average of 15% and therefore the pack would remain at a safe 35% SOC. Zero’s biggest fear is the cells self-discharging to a critical level and the need of replacement under warranty. With this in mind, they figure as long as the charger is plugged in and working everything will be in order. However, Zero's procedure fails to consider the owners safety and fire risk in the event of the a BMS failure or a spike causing a the processor to freeze and not terminate the charge.
The Zero's BMS is of a "simple low cost" design and prone to failure - there are hundreds of threads and Google searches to validate that owners have constant failures - so why would anyone lock up their house for months at a time and leave the bike plugged in? Its a senseless decision when storing the bike as I recommended will better protect the health of the battery and most important remove the risk of the owner losing their home or even possible death from a lithium fire.
You guys have to ask yourself the question of why would anyone trust the advise of a company that does not even have the know how to get a simple App to work ?
Is any of this starting to make sense now?
Regards
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Let's say a bike was left unplugged in enclosed storage for like.. 4 months? a year? I suppose the best thing to do would be to plug it in right away before attempting to turn it back on?
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Let's say a bike was left unplugged in enclosed storage for like.. a year. I suppose the best thing to do would be to plug it in right away before attempting to turn it back on?
Thanks for the reply - it won't matter if you turn it on or charge it - but storing it for 12 months you would want the SOC charge state to be at 80-85% since self-discharging will drop the battery around 30% for 12 months.
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I would want the SOC state to be that? You mean, that's what you would expect it to have dropped? Will it charge back up to 100% ok, or will the battery capacity be permanetly lowered?
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User Low On Cash is mostly right. Cells don't like being stored at full SOC, it shortens the cycle life. But there is a reason why Zero recommends leaving the charger plugged in.
I am not sure where this idea that there is a 2-3% self discharge every month came from but it isn't true with Farasis's cells. The self discharge rate is heavily dependent on chemistry, temperature, and SOC. After extensive testing with these cells, at higher SOC (70-90) Farasis's cells will self discharge maybe around 1-1.5% a month while at lower SOC its much less. So much less that the amount of current the BMS draws is more important than the self discharge rate.
Other people have already said it but Zero only charges the battery to 4.15V which is not full capacity of the battery. The area that hurts cycle life the most is between 4.15V and 4.2V, any thing higher than 4.2V it is considered dangerous (I can explain why if people are curious).
I store my bike around 40-60%, this is what Farasis stores their batteries at. While leaving the bike on charge isn't the best for it's cycle life it shouldn't cause any fire. In the event the BMS locks up it can't do anything but open or close the contactors. There is also the MBB on the bike that can protect the bike in the event of a non-responding BMS. If the charger dies due to surge or something then the BMS will open the contactors due to a non responding charger.
The ways to get a battery fire is to put it in a super hot environment, or over discharge the battery then try to charge it back up, or over charge the battery. Leaving the bike on charge can't cause either of those scenarios. Leaving the bike plugged in won't allow for an over discharge, and since the charger won't go higher than 116V you can't over charge your battery plus the BMS and MBB are there to oversee things. In the event of the BMS and the MBB not responding and the contactor is welded and the charger some how outputs more than 117.6V then yes there is a risk of fire. This is probably why Zero ask you to check on it every 72 hours to make sure the bike is still responding and the BMS is still alive. Also just to clear things up there has never been a fire with a production Zero bike that uses Farasis cells (this doesn't count prototypes and test bikes).
I think someone said that Zero’s BMS is like $20-30. Not true, the parts on there alone are like $40 not counting the PCB, potting, and assembly cost. Their BMS is not perfect and has some known flaws but they are making them better each year. But when it comes to protecting the battery the BMS does a really good job and won’t close the contactor if there is anything out of the ordinary. I think the Zero BMS uses some of the same parts in the Tesla Model S BMS.
So the reason Zero says to leave the bike plugged in is that it prevents over discharge and there shouldn't be any over charging because they left some margin and there are many things that needs to fail to over charge. This does hurt cycle life on the cells, but its better then having either an over discharge or over charge situation.
Also something else that people might not know. Without saying too much there are a few magic secret things in those battery pack and cell pouches that in the event of thermal runaway or fire they will limit the current flow and suppress any damages. There is a reason why Zero pay a premium for these pouch cells and not cylinder cells like other people
Sometimes it may not be clear why engineers including those at Zero and Farasis do what they do but I assure you that they are concern with safety and they always have to evaluate the risks. I am sure someone will say that I am wrong but I think I will leave at that.
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I am not sure where this idea that there is a 2-3% self discharge every month came from but it isn't true with Farasis's cells. The self discharge rate is heavily dependent on chemistry, temperature, and SOC. After extensive testing with these cells, at higher SOC (70-90) Farasis's cells will self discharge maybe around 1-1.5% a month while at lower SOC its much less. So much less that the amount of current the BMS draws is more important than the self discharge rate.
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I store my bike around 40-60%, this is what Farasis stores their batteries at. While leaving the bike on charge isn't the best for it's cycle life it shouldn't cause any fire. In the event the BMS locks up it can't do anything but open or close the contactors. There is also the MBB on the bike that can protect the bike in the event of a non-responding BMS. If the charger dies due to surge or something then the BMS will open the contactors due to a non responding charger.
The ways to get a battery fire is to put it in a super hot environment, or over discharge the battery then try to charge it back up, or over charge the battery. Leaving the bike on charge can't cause either of those scenarios. Leaving the bike plugged in won't allow for an over discharge, and since the charger won't go higher than 116V you can't over charge your battery plus the BMS and MBB are there to oversee things. In the event of the BMS and the MBB not responding and the contactor is welded and the charger some how outputs more than 117.6V then yes there is a risk of fire. This is probably why Zero ask you to check on it every 72 hours to make sure the bike is still responding and the BMS is still alive. Also just to clear things up there has never been a fire with a production Zero bike that uses Farasis cells (this doesn't count prototypes and test bikes).
I think someone said that Zero’s BMS is like $20-30. Not true, the parts on there alone are like $40 not counting the PCB, potting, and assembly cost. Their BMS is not perfect and has some known flaws but they are making them better each year. But when it comes to protecting the battery the BMS does a really good job and won’t close the contactor if there is anything out of the ordinary. I think the Zero BMS uses some of the same parts in the Tesla Model S BMS.
So the reason Zero says to leave the bike plugged in is that it prevents over discharge and there shouldn't be any over charging because they left some margin and there are many things that needs to fail to over charge. This does hurt cycle life on the cells, but its better then having either an over discharge or over charge situation.
Also something else that people might not know. Without saying too much there are a few magic secret things in those battery pack and cell pouches that in the event of thermal runaway or fire they will limit the current flow and suppress any damages. There is a reason why Zero pay a premium for these pouch cells and not cylinder cells like other people
Sometimes it may not be clear why engineers including those at Zero and Farasis do what they do but I assure you that they are concern with safety and they always have to evaluate the risks. I am sure someone will say that I am wrong but I think I will leave at that.
Higher discharge rate is quoted as a conservative estimate in case there is a battery defect or a board / systems defect. The idea is predicting a safe visit / check frequency from some basic assumptions to maybe corroborate the official recommendations or provide a reasonable fallback.
Thanks for clarifying everything else. It's been clear since the first battery engineer posted about Farasis here on the forum that being left plugged in unattended was considered a reasonable but not optimal recommendation. I'm pretty sure we've already nailed a better set for recommendations but your feedback is worth incorporating for better depth of understanding.
Not to pry, but how do you know Farasis' practices and accident statistics?
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Not to pry, but how do you know Farasis' practices and accident statistics?
I guess I should have mentioned that I work for Farasis designing BMS and a bunch of the Zero engineers are my good friends.
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User Low On Cash is mostly right. Cells don't like being stored at full SOC, it shortens the cycle life. But there is a reason why Zero recommends leaving the charger plugged in.
I am not sure where this idea that there is a 2-3% self discharge every month came from but it isn't true with Farasis's cells. The self discharge rate is heavily dependent on chemistry, temperature, and SOC. After extensive testing with these cells, at higher SOC (70-90) Farasis's cells will self discharge maybe around 1-1.5% a month while at lower SOC its much less. So much less that the amount of current the BMS draws is more important than the self discharge rate.
Other people have already said it but Zero only charges the battery to 4.15V which is not full capacity of the battery. The area that hurts cycle life the most is between 4.15V and 4.2V, any thing higher than 4.2V it is considered dangerous (I can explain why if people are curious).
I store my bike around 40-60%, this is what Farasis stores their batteries at. While leaving the bike on charge isn't the best for it's cycle life it shouldn't cause any fire. In the event the BMS locks up it can't do anything but open or close the contactors. There is also the MBB on the bike that can protect the bike in the event of a non-responding BMS. If the charger dies due to surge or something then the BMS will open the contactors due to a non responding charger.
The ways to get a battery fire is to put it in a super hot environment, or over discharge the battery then try to charge it back up, or over charge the battery. Leaving the bike on charge can't cause either of those scenarios. Leaving the bike plugged in won't allow for an over discharge, and since the charger won't go higher than 116V you can't over charge your battery plus the BMS and MBB are there to oversee things. In the event of the BMS and the MBB not responding and the contactor is welded and the charger some how outputs more than 117.6V then yes there is a risk of fire. This is probably why Zero ask you to check on it every 72 hours to make sure the bike is still responding and the BMS is still alive. Also just to clear things up there has never been a fire with a production Zero bike that uses Farasis cells (this doesn't count prototypes and test bikes).
I think someone said that Zero’s BMS is like $20-30. Not true, the parts on there alone are like $40 not counting the PCB, potting, and assembly cost. Their BMS is not perfect and has some known flaws but they are making them better each year. But when it comes to protecting the battery the BMS does a really good job and won’t close the contactor if there is anything out of the ordinary. I think the Zero BMS uses some of the same parts in the Tesla Model S BMS.
So the reason Zero says to leave the bike plugged in is that it prevents over discharge and there shouldn't be any over charging because they left some margin and there are many things that needs to fail to over charge. This does hurt cycle life on the cells, but its better then having either an over discharge or over charge situation.
Also something else that people might not know. Without saying too much there are a few magic secret things in those battery pack and cell pouches that in the event of thermal runaway or fire they will limit the current flow and suppress any damages. There is a reason why Zero pay a premium for these pouch cells and not cylinder cells like other people
Sometimes it may not be clear why engineers including those at Zero and Farasis do what they do but I assure you that they are concern with safety and they always have to evaluate the risks. I am sure someone will say that I am wrong but I think I will leave at that.
Wontuan thanks for your detailed reply - it is greatly appreciated and it confirms a lot of speculation.
Regards - Mike
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Of course if your bike never sits still for more than a couple of days, storage isn't much of an issue. 😉
Sent from my Z981 using Tapatalk
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In my years in the model industry, I have seen first hand many of my co-workers homes and business burnt to ground as a result of lithium cells.
Wow, that's a bit inflammatory ;)
But seriously, dude, I'm thinking you should sell your zero. Sounds like a disaster waiting to happen!
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Of course if your bike never sits still for more than a couple of days, storage isn't much of an issue. 😉
What HE said!! :D
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Hello Zero Owners - Sorry I didn’t get this up sooner - since this very thread brought up safety concerns of Zero’s recommended “UnAttended Chargingâ€, Zero has changed their policy and now does not recommend leaving the bike on charge for long periods of time since there is possibility of an over-charging the pack which would result in the pack igniting in fire.
I would like to personally thank the folks at Zero for taking the immediate incentive to correct their “Long Term Battery Storage†recommendations for the Zero motorcycle.
I’m certain my safety concerns posted on this thread, combined with my personal letter to Zero with my concerns regarding the “Fire†risk of unattended charging was instrumental to their decision.
As I indicated in my remarks on this thread and my letter to Zero’s Corporate office, due to very low self-discharge rates of current lithium cells, there is no benefit in having the bike powered and unattended for long periods of time. As I outlined in this thread a safer method of simply discharging the cells to 60-70% SOC provides better health for the pack and most important allows the bike to be un-plugged for long term storage therefore removing the possibility of charging circuitry failure, which may result in an over-charged SOC, resulting in a fire threat, loss of property or even death as we have witnessed numerous times with other lithium powered vehicles and devices.
Best Regards - Mike Mas
(http://www.com-pany.com/zero/zeropolicy .jpg)
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I've reported your latest comment for deliberately mischaracterizing Zero's statement again. Let's lock this thread, please.
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And please somebody buy his DSR, then he'll have no reason to hang around.
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(http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_16763.jpg)
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If everyone has said their piece I can lock this thread. The great thing about discussion forums is people can say what they think and others can support or deny it. What is posted may or may not be true. Leaving a thread unlocked allows folks with the truth to share it if it's the latter.
Most folks on this board are intelligent enough to think twice and verify what they read so I'm less inclined to lock a thread.
Locking threads may just send people to other forums to post the same thing there. Why not just beat it to death in one place and call it done?
Pm me if you have thoughts one way or another. I'm interested.