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Messages - wontuan

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1
Zero Motorcycles Forum | 2013+ / Re: Zero has released 2018 models.
« on: October 19, 2017, 01:49:44 PM »
Quote from: Erasmo on October 19, 2017, 12:46:20 PM
Does somebody know if the new Charge Tank is single phase?

The new charger work with J1772 which are single phase AC. This probably means they are just 240v single phase chargers.

The new cells are 32Ah but there is more to the these cells then just a capacity bump. =) It'll be interesting to see what people think of them.

2
Zero Motorcycles Forum | 2013+ / Re: CHASSIS ISOLATION DANGER: 2 KOhms to cell 2
« on: June 29, 2017, 10:30:19 PM »
Leave the batteries disconnected and measure resistance with a DMM from B- to chassis/heatsink on the sevcon controller.

3
Zero Motorcycles Forum | 2013+ / Re: Lithium Ion (Li-ion) Batteries used in Zero Motorcyles - all you need to know
« on: June 07, 2017, 12:40:02 PM »
Bare brick is about 38lb

4
Zero Motorcycles Forum | 2013+ / Re: Change to Charging - Leaving Bike Plugged In
« on: March 27, 2017, 02:24:02 AM »
Quote from: Low On Cash on March 27, 2017, 01:38:37 AM
Quote from: wontuan on March 26, 2017, 11:53:26 PM
Quote from: Low On Cash on March 26, 2017, 07:33:08 PM
LOL you guys really amaze me - you're so afraid to admit when someone is right you would rather twist the facts around to suit your agenda even at the risk of saving someones home or life.  It amazes me a Public Forum would accept the responsibility to mask my thread which will avoid a potential danger!

Just to clear the air here's a quote from Farasis from this very same forum and further backed by Zero's new unattended charging policy:

"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."

Be Safe - Mike Mas

Ok so you are quoting me.
Here is the post he is referring to:
http://electricmotorcycleforum.com/boards/index.php?topic=6583.45

I don't care for arguing how people interpret things but I do care about people using the Farasis name. What I said in the post were my words as an individual sharing my limited knowledge. I don't represent Farasis and no one on this forum represents Farasis.

About the lighting thing. If your house has a big enough surge from lighting it could destroy the on board charger, but it shouldn't do anything to the BMS. The charger is an isolated power supply with suppressors on the input so if the surge if big enough the suppressors will fail short.  Then your breaker should fail after that. The BMS and the rest of the bike is completely isolated from the charger so I don't see a current path there. This is why some people on this forum reports their charger is dead but the bike is fine and there wasn't any fire and most of the time Zero replaces the onboard charger for them. I can't think of any technical way the BMS would be affected. Let me know if someone has an answer to that.


Wontuan - thanks for your reply - sorry you got dragged into this but a user quoted your reply, so I responded, however you might want to clarify your last post on your position with Farasis and Zero because when Brian asked you; " Not to pry, but how do you know Farasis' practices and accident statistics?" 

Your reply was:

"I guess I should have mentioned that I work for Farasis designing BMS and a bunch of the Zero engineers are my good friends."


I really don't see what is left to debate here or why there is so much aggression towards me. I'm just a rider like you guys who discovered an error in unattended charging and put up a post with my safety concerns then followed it up with a report to Zero. Evidently my concerns were valid since Zero's reply was:

"For planned long-term storage (more than 30 days), we recommend draining the power pack to a 60% state of charge, and leaving the charger unplugged. The key change is we are dropping the guideline/requirement that you must or should keep it plugged in all the time." 



Zero's revised procedure is the same I outlined in my now "Closed Thread" so why do a select group of guys find fault with the issue and continue attacking me.  I am publicly asking the administrators to "Re-open" my Safety thread to avoid it from disappearing from the view of newcomers who visit the forum who are not aware of this potential dangerous charging procedure. Why would this forum want to mask something that can be an dangerous to riders? There is nothing in the thread that violates Forum rules so please re-open my thread!

Mike Mas

Mike,

I am ok with people quoting me, even saying "an employee of Farasis said ..", but the things I comment on are from my knowledge and perspective. I do not represent Farasis what so ever. Just like everyone else I could be wrong. You are more then welcome to quote me, just don't say it was Farasis that confirmed anything. This goes for everyone on this forum, do not quote me or anyone else and say that Farasis said it. If Farasis has something to say they will inform their customers.

You are correct that Zero did revised their recommendation. This is to help users increase their battery life cycles. I do see that there has been some aggression going on and I think it is because you insist that there is a risk of fire. Which people view as a false claim. I believe that people do agree with you that leaving the bike plugged in isn't great for the battery cycle life, they just don't agree that there is any fire risk and that Zero changed the recommendation due to a risk of fire. If you truly believe there is a fire risk then try to form a compelling argument with information to back it up. For example if you think a lighting surge can cause damage to the BMS then ask others if they know what kind of surge suppression Zero has on the bike or if the bike is complete isolated from the AC outlet. I encourage you and everyone else to express concerns but also try formulate technical reasons to backup your concerns. Having a good discussion is what forums are about.

With that being said let me provide some information on some assumptions that have been made.
1. BMS not responding
If the BMS doesn't response the contactor will open because they are normally open contactors. While failed BMS have been reported, it is more likely the AFE chips drained some cells or won't close the contactors. The BMS was design to fail in a safe state.

2. MBB not responding
I have never heard of this happening, but who knows.

3. the contactor is welded
Contactor doesn't just weld when they are closed, they weld during closing event. The common way for a contactor to weld is if there is no pre-charging systems and the contactor closes and there is an arc across the contactors and it melts the copper and welds it shut. This happens on high voltage closing events, not opening or already closed.
https://support.industry.siemens.com/cs/document/22979862/reasons-for-contact-welding-in-contactors?dti=0&lc=en-WW

4. the charger some how outputs more than 117.6V
I have no idea how this will happen. The charger is an isolated AC to DC charger with surge protection on the AC input and DC output. The BMS can tolerate high voltage so even a high spike the BMS won't care at all. Each cell has voltage clamps across them to limit the voltage on each cell.  Also each cell can tolerate a spike on them, its sustained over-voltage that is bad.

If I have provide any incorrect information please let me know.
Again, I think conversations like this should be welcomed but lets keep it a conversation instead of a back and forth name calling thread.

5
Zero Motorcycles Forum | 2013+ / Re: Change to Charging - Leaving Bike Plugged In
« on: March 26, 2017, 11:53:26 PM »
Quote from: Low On Cash on March 26, 2017, 07:33:08 PM
LOL you guys really amaze me - you're so afraid to admit when someone is right you would rather twist the facts around to suit your agenda even at the risk of saving someones home or life.  It amazes me a Public Forum would accept the responsibility to mask my thread which will avoid a potential danger!

Just to clear the air here's a quote from Farasis from this very same forum and further backed by Zero's new unattended charging policy:

"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."

Be Safe - Mike Mas

Ok so you are quoting me.
Here is the post he is referring to:
http://electricmotorcycleforum.com/boards/index.php?topic=6583.45

I don't care for arguing how people interpret things but I do care about people using the Farasis name. What I said in the post were my words as an individual sharing my limited knowledge. I don't represent Farasis and no one on this forum represents Farasis.

About the lighting thing. If your house has a big enough surge from lighting it could destroy the on board charger, but it shouldn't do anything to the BMS. The charger is an isolated power supply with suppressors on the input so if the surge if big enough the suppressors will fail short.  Then your breaker should fail after that. The BMS and the rest of the bike is completely isolated from the charger so I don't see a current path there. This is why some people on this forum reports their charger is dead but the bike is fine and there wasn't any fire and most of the time Zero replaces the onboard charger for them. I can't think of any technical way the BMS would be affected. Let me know if someone has an answer to that.

6
Zero Motorcycles Forum | 2013+ / Re: Change to Charging - Leaving Bike Plugged In
« on: March 26, 2017, 07:27:03 AM »
Quote from: Low On Cash on March 26, 2017, 06:37:44 AM
both Zero's recent change in charging policy and further confirmed by Farasis.
Regards - Mike

Farasis did not confirm anything. Please don't make those claims. If Farasis is worried about a safety issue they will let their customers know. If you are referring to my comment on your previous thread then I suggest you reread that it cause I clearly said:

Quote
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.

I did go into the chain of events that must happen to even cause over-charging and the likeliness of those all happening is close to  impossible. I also mentioned that there are even more safety systems that most people don't know about in those batteries. I really don't like these kind of conversations but lets address some key points.

You are correct, it isn't good to over charge your cells. This increases the likely hood of a fire but doesn't guaranty it. It does matter who makes the lithium cells because the type of chemistry matters a lot and I can tell you that there are a lot of different types of lithium cells.

Even in the event of a BMS failure it is more likely that the BMS will drain the cells because it left the balancers on, it won't allow for an over charge. Like I said even if the BMS fails there is a many other systems in place to open the contactor and prevent any over charging. The onboard charger won't over charge batteries, it won't go above 116. Trust me, it just won't. It is true that leaving the bike plugged in isn't the best for it's heath (even Zero admits that) but it does not post a fire risk.

You can't compare a Zero to those hover board fires because most those hover boards didn't even have a BMS or any form of safety system. They were made to be cheap unlike a Zero that costs many thousands of dollars.

I understand your worries and I appreciate you expressing your safety concerns. I ask that you trust the engineers to make the best decisions because they do take safety seriously. With that being said I think people are giving you hate because they feel that you are dismissing or misinterpreting Terry and the Zero engineers. I think you have already expressed your views and I don't think there is any need to reiterate it. If you have any concerns or question I would be more then happy to clear things up or ease your worries. PM me.

7
Zero Motorcycles Forum | 2013+ / Re: acceleration 2016 SR vs 2017 SR vs 2017 DSR
« on: March 24, 2017, 02:20:59 PM »
Quote from: kashography on March 24, 2017, 11:27:00 AM
But i also think 2.7 is not realistic

A stock DSR probably won't do 2.7s 0-60mph. I think my 16' S can get close to 3s (it's not stock) and it should break 2.7s after I change the gearing ratio. I have been on a DSR that definitely does 2.7s easily.

Also, the SR and DSR are very similar. The SR is a hair faster due to the aerodynamics and the tires have a tad more grip but the DSR wheelies easier cause of the bigger wheels.

8
Zero Motorcycles Forum | 2013+ / Re: 2014 Zero DS dead?
« on: March 20, 2017, 12:34:26 AM »
Quote from: Mr. Fusion on March 19, 2017, 11:04:17 PM
it's measured from the BMS connector to the cells. So probably directly...

Let's see how the cells react to some current...

If it is true that your BMS is off and the cells are at 0.4v I would recommend you not try to charge them up. Your cells are considered dead and shouldn't be charged up. Charging over-discharged cells is dangerous and it is recommended that you contact Zero right away with your findings and let them help you replace the battery.

9
Zero Motorcycles Forum | 2013+ / Re: My homemade 'Supercharger' for a ZERO Version 2
« on: March 13, 2017, 05:56:39 AM »
Quote from: remmie on March 11, 2017, 04:01:00 AM

In this thread on endless sphere a guy has made a board for the Flatpack S

https://endless-sphere.com/forums/viewtopic.php?f=14&t=71139&hilit=ultra&start=175#p1270667

the chargers in this picture is definitely a flatpack S 1800 W


Ah that's my old board. I was asked if I could make the board public. It was the first one I made for testing so things are a lot more spaced out and with bigger holes. I do have a stubby version but I didn't like it as much cause it would be hard to disconnect quickly. The board has two holes for each connection so you can connect between the two FPS.
Remmie is correct, the FPS and FP2HE are a bit different.

Be safe and have fun!



10
Zero Motorcycles Forum | 2013+ / Re: Advanced BMS Self Discharging Feature & Zero Cell Storage
« on: March 10, 2017, 11:17:52 PM »
Quote from: BrianTRice on March 10, 2017, 09:36:41 PM

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.

11
Zero Motorcycles Forum | 2013+ / Re: Advanced BMS Self Discharging Feature & Zero Cell Storage
« on: March 10, 2017, 11:28:16 AM »
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.


12
Zero Motorcycles Forum | 2013+ / Re: Solar charging
« on: March 04, 2017, 03:05:01 PM »
I don't want to tell you that you can't do something but let me explain why Genasun said it's a waste of your time to make a portable PV charging system for a Zero.
The current state of solar technology just can't produce the power to charge a Zero in a reasonable amount of time (2-3 days) and be portable and small. I know the argument here is that the technology will get better and that some day we will have panels that can supply so much power. This is true,  panels will get better, but they will never get to the power level you need. The highest consumer solar cells right now are like 22% efficiency (SunPower and SolarCity cells, not counting space-space solar tech) and there are some gallium arsenide cells that approach 32% efficiency and they will get better but even at 100% efficiency it still won't be enough. This is because there is only about 1kw/m2 of solar power hitting the earth's surface, this is what people mean when they say an irradiance of "1 Sun". There are some high altitude areas where I have seen 1.2 Sun (1200kw/m2). So if you had a solar panel that rolled out to be a meter squared and had 100% efficiency (not possible btw look up Shockley–Queisser limit) you would only generate 1kwh every hour ( assuming 100% efficiency in wiring, charger, module glass, and DC-DC converter). There are only 2-3 hours in the day where you would get peak power so you would generate maybe a max of 4kwh a day. So to charge a ZF9.8 you would need a little more than two days using the 100% square meter of PV and both days would have to be fair sunny. By the time we get this 100% efficient panels battery tech will have advanced so far that you may not need to charge at all. If you still want to pursue this portable camping PV charger let me know if you make any break through because if you can generate more than 1Kw/m2 using PV I would like to invest in whatever company you plan to start.

I think your time and money is better spent on getting a fast charger and using the RV plugs at camp sites to charge. This is something I do and it works great. I just find an RV 14-50 socket and then in an hour I am almost full on my ZF9.8.

13
Zero Motorcycles Forum | 2013+ / Re: Solar charging
« on: March 01, 2017, 12:38:51 PM »
Former solar engineer who now works on battery tech stuff here.

I have helped charged Zero monoliths from some solar panels before and I am currently doing another setup where I have some big panels charging batteries that I use to charge a Zero nightly. Here are some things you want to consider before attempting to charge batteries via solar panels:

1) Solar panel ratings are always optimistic, I know cause I used to work on solar modules.

2) The output power isn't a continuous rating, you will see that the panels output peak power around 11am - 1am depending on your climate and how bright it is. Hot temperature decreases power output.

3) If you don't have an MPPT controller then you aren't going to get one then your efficiency will suffer a lot. The panel's behavior is defined by it's IV curve and there is a point on that curve where it produces the most power. This is where the MPPT controller will try to keep it at. For example if the panel has a Vmp (the voltage where it produces the most power) of 17.8v and your battery can be any where from 90v to 116v and you want to have 9 panels in series, at 90v each panel will be at 10v (assume they are balanced) which is far from their the 17.8v they should be at. At 116v they would be at 12v which is still far from the 17.8v. It might be more efficient to get an MPPT controller that outputs 120vac and just use your onboard charger.

4) You need a disconnect system, meaning when the voltage gets to 116v the panel better stop providing power or else it will over charge the cells. The BMS will open the contactor some where after 117v but opening a contactor under load stress the contactor.

5) Also make sure you have a way to prevent the battery from dumping current in to the panels. Yes this happens and the panels really don't like it. Just put a nice outdoor rated blocking diode between the panel and battery. The diode will always be conducting and producing heat so you got some power lost there and you have to make sure the diode can survive the constant stress and heat.

There are other things to consider but I don't want to get into this unless people ask for it. I am not trying to discourage people from using solar panels to charge things, in fact I do it myself and I have helped other people do it. But the I am fortunate to have lots of batteries and lots of panels so efficiency isn't a big deal for me. Solar technology is moving pretty fast but it will still be awhile before we get a  small and simple solution that will charge our bikes within a day or two. I wouldn't recommend any kind of camping charging solution unless you plan to be charging for 1-2 weeks. Home charging solutions aren't super hard. Just make sure you are being safe and have an electrician or someone who knows what they are doing look at it. For most people I would recommend connecting panels to an MPPT controller that outputs 120Vac and using the onboard charger because it's safer, simpler, and probably more efficient then doing DC-DC charging.

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