ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: flynnstig82r on April 07, 2021, 02:19:40 AM
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https://www.bluetti.com/products/bluetti-ac30s-300wh-300w-portable-power-station-1
I looked at the listing for this portable power station and thought maybe it could prevent getting stranded if I were limping home or to a charge station and didn't quite make it. The 300 Wh would provide another few miles and might be preferable to pushing the bike.
However, with only a 300w output, would the OBC or charge tank w/ turbo cord just trip this thing's breaker immediately? Or would one of those 2 chargers know to only pull 300w?
Is there a better small, lightweight solution than this portable power station that could add another ~2 miles range in a pinch?
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Would the cost (in energy used) to carry this battery, possibly all the time, be worth the charge you could get from it? How many times have you actually drained your battery to 0 range available and had to push / tow your way to the next charger? I've had the same range anxiety on a gas bike that I've had on my Zero. Running on fumes trying to get to the next gas station after I switched the petcock to reserve, feels the same as watching the SOC tick down from 5.. 4.. 3.. 2.. 0. All the while knowing my distance to the next station. Both situations are a result of poor planning on my part. Ultimately I think if you need the extra range to get between chargers, you need a bigger battery, not an 300W accessory.
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You need a 2000W supply to charge using an S-platform charger. That won't do it. A 1200W supply might do for an X-platform charger.
-Crissa
PS - I have tried a 1500W supply on my S and it tripped immediately ^-^;
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Would the cost (in energy used) to carry this battery, possibly all the time, be worth the charge you could get from it? How many times have you actually drained your battery to 0 range available and had to push / tow your way to the next charger?
Twice in seven days, but I'm a new owner so those were rookie miscalculations.
I've had the same range anxiety on a gas bike that I've had on my Zero. Running on fumes trying to get to the next gas station after I switched the petcock to reserve, feels the same as watching the SOC tick down from 5.. 4.. 3.. 2.. 0. All the while knowing my distance to the next station. Both situations are a result of poor planning on my part. Ultimately I think if you need the extra range to get between chargers, you need a bigger battery, not an 300W accessory.
All very true, but I doubt I'm going to stop planning poorly any time soon. ;)
Also thanks to Crissa for the info!
I can see those small power stations aren't going to cut it, but I'm still attracted to the idea of a limp-home battery, something equivalent to carrying a pint of gasoline to make it to the next station on a traditional motorcycle. A quick perusal of IMRbatteries shows Molicell 21700 4000mah 45A cells going for $5.50 each. A 28S1P pack would have equivalent voltage to Zero's monolith and 1/25th of the capacity, enough to make it an extra couple of miles. The cells would weigh just over 4 lbs and could be arranged in a relatively flat pack that could sit on the inside of a top case lid or maybe a cylindrical pack that could slot into the "bonus storage" on the SR's swingarm.
The tricky parts would be inverting the power so the charge tank or OBC would accept the charge (unless they can take 116v DC, I'm assuming they can't) and designing an enclosure safe enough for >60 volts as a hobbyist. If I were to add Diginow SC's, that would solve the first problem.
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Related question: Is it possible to charge while riding?
If I could see that I probably wasn't going to make it to the next charger, I'd probably rather hook up the hypothetical auxiliary battery and continue riding than lose power unexpectedly and possibly get rear-ended before pulling over to hook it up.
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Related question: Is it possible to charge while riding?
This could be probably be done through the auxiliary port, but you'd need 116V or whatever to push into it. Then it's the same as "get a bigger battery" like a power tank.
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Interesting! I would assume that using the aux port in this way would require a DigiNow SC or other charger that can accept DC input?
The power tank doesn't solve the problem. I might still miscalculate and need the small boost once in a blue moon. Of course, in an ideal world I'd never miscalculate but I've already done it twice so it would be nice to have a bailout solution other than pushing a bike along a highway or waiting hours for a tow truck.
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You could probably store that many batteries in the wings of the plastic.
But lithium doesn't like sitting around full.
-Crissa
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Would the cost (in energy used) to carry this battery, possibly all the time, be worth the charge you could get from it? How many times have you actually drained your battery to 0 range available and had to push / tow your way to the next charger?
Twice in seven days, but I'm a new owner so those were rookie miscalculations.
I've had the same range anxiety on a gas bike that I've had on my Zero. Running on fumes trying to get to the next gas station after I switched the petcock to reserve, feels the same as watching the SOC tick down from 5.. 4.. 3.. 2.. 0. All the while knowing my distance to the next station. Both situations are a result of poor planning on my part. Ultimately I think if you need the extra range to get between chargers, you need a bigger battery, not an 300W accessory.
All very true, but I doubt I'm going to stop planning poorly any time soon. ;)
Also thanks to Crissa for the info!
I can see those small power stations aren't going to cut it, but I'm still attracted to the idea of a limp-home battery, something equivalent to carrying a pint of gasoline to make it to the next station on a traditional motorcycle. A quick perusal of IMRbatteries shows Molicell 21700 4000mah 45A cells going for $5.50 each. A 28S1P pack would have equivalent voltage to Zero's monolith and 1/25th of the capacity, enough to make it an extra couple of miles. The cells would weigh just over 4 lbs and could be arranged in a relatively flat pack that could sit on the inside of a top case lid or maybe a cylindrical pack that could slot into the "bonus storage" on the SR's swingarm.
The tricky parts would be inverting the power so the charge tank or OBC would accept the charge (unless they can take 116v DC, I'm assuming they can't) and designing an enclosure safe enough for >60 volts as a hobbyist. If I were to add Diginow SC's, that would solve the first problem.
In the old days motorcycles had limp home mode. You had a petcock that could be switched to "reserve" when you ran out of fuel. With more accurate modern fuel gauges these became unnecessary.
To get extra range there are tricks like "halving the speed gives you twice the range", run with the bike, put more pressure in the tires, go on that diet ;D.
Here is an idea. Instead of carrying extra batteries, modify your BMS to keep 10% in reserve. Then, when you run out, you can push a button to activate the last 10%.
What I'm trying to say is that the weight of the extra battery will have negative effect on range. It is IMHO better to try to be more conservative when estimating range.
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The great thing about running out on my SR/F is that in practice it never actually happens!
My experience is that i missed a service station ( not paying attention) and kept going hoping i would make the next one, 25 miles away. I was cruising at 70 mph to start with, watching the caudated range drop faster than the mileage signs. So I slowed down, 60, 10 mins later 50, then quite quickly as I realised I was in trouble to 50, 40. At this point I was in danger of being rear ended on the highway, so I cut the speed to 30 mph and drove on the hard shoulder, cars wizzing past. I got to 1% left and saw an early exit which I took, thinking its better to be rescued off the high way. Then I realized that my early speed/load reduction had worked, but not enough and the bikes own restrictions started to cut in. I actually travelled about a mile on the pavement (unoccupied!) with zero on the SOC, doing 6-8mph to the service station.
This was freaky, but I learnt that the BMS has in fact got a limp home feature built in, which was kinda reassuring. However, I note I went home and paid £86 for a years motorbike recovery, as the other lesson I got quite clearly is that there is no way I can push this thing for a mile on the level, let along any slight hill/bump.
Hope this helps.
pete
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I think the additional weight and inconvenience of carrying a second battery large (heavy) enough to charge the bike will be a problem. This may sound flippant, but the right answer is to not run out of power.
I would choose an ICE bike before doing what you suggest.
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or indeed... the power tank.
Cas :)
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The backup battery that I envision would weigh just over 4 lbs in cells. Not large or heavy, just enough to eke out another mile or two of range and avoid calling the tow truck.
The power tank is not a solution to this problem. The point of the battery is not that I need an extra mile or two of total range, it's to bail me out after I've already miscalculated and can't make it to the next charger. I can just as easily miscalculate and run to nothing with a power tank as without.
For instance, when I had to push the last 3 blocks to make it home, it was because I didn't spend enough time at the charging stop in Oakland prior to attempting the last leg of the trip over the Bay Bridge. I tried to give myself an extra 5% reserve and thought that my SR could cover a similar ~5 extra miles after running to 0% like the SR/S I had rented the previous week. The strong headwind made me run out a lot sooner than expected but I was already on the Bay Bridge with no option to exit or to go slower without risking a rear-end collision. If the bike had started cutting power even a 1/2 mile sooner, I would have been forced to call a tow truck, as there would have been no way to make it the rest of the way across the bridge safely.
Not screwing up in the first place would of course be preferable, but I'd rather have the extra safety net and not need it than need it and not have it. Keeping a reserve is an interesting idea, but I'd hate to lose the last 10% range, and modifying the OEM BMS sounds like a much bigger project than building what amounts to a small e-bike battery.
The first order of business will be to increase charge rate. 3.8 kW is just not cutting it, and I would have spent the extra time adding another 10% if it didn't mean standing around in a sketchy Walgreens parking lot for another 20 minutes. If I can add range much more quickly at charging stops, I might not need the limp-home battery, but it would still be nice to know it's there.
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The great thing about running out on my SR/F is that in practice it never actually happens!
My experience is that i missed a service station ( not paying attention) and kept going hoping i would make the next one, 25 miles away. I was cruising at 70 mph to start with, watching the caudated range drop faster than the mileage signs. So I slowed down, 60, 10 mins later 50, then quite quickly as I realised I was in trouble to 50, 40. At this point I was in danger of being rear ended on the highway, so I cut the speed to 30 mph and drove on the hard shoulder, cars wizzing past. I got to 1% left and saw an early exit which I took, thinking its better to be rescued off the high way. Then I realized that my early speed/load reduction had worked, but not enough and the bikes own restrictions started to cut in. I actually travelled about a mile on the pavement (unoccupied!) with zero on the SOC, doing 6-8mph to the service station.
This was freaky, but I learnt that the BMS has in fact got a limp home feature built in, which was kinda reassuring. However, I note I went home and paid £86 for a years motorbike recovery, as the other lesson I got quite clearly is that there is no way I can push this thing for a mile on the level, let along any slight hill/bump.
Hope this helps.
pete
That's how the SR/S was. I didn't quite get to the 6-8 MPH level that you did, but I got to the point where it the top speed was about 35 MPH, which reminded me of the Scoot mopeds at my old job. My 2017 SR was much more abrupt. It started severely limiting top speed soon after hitting 0% SoC and giving too much throttle would shut down the whole bike and it would need to be power cycled with the ignition key. I was able to make it most of the way back through the city in the bike lane by being extremely gentle with the throttle in eco mode, but once the top speed dropped below about 20 MPH, it shut off for the last time and refused to start again until I pushed it home and plugged in.
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My 2018 S with PT was good for over 3 miles at 25mph while climbing a 12% grade after the SOC display read "00". I don't know how much further it would have gone, but I heard someone in the past mention 10 miles on level ground was in the pot after SOC read empty. ??? However, no doubt that depends upon the overall condition of your battery pack.
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I have noticed the more I ride in a temperature range, the more correct the SOC is and the more that's available at the bottom.
I think the bike tries its best to leave somee down there, it just doesn't always know where the cells have lost their plasticity without practice. And cells might need that conditioning to get the most out of them)
-Crissa
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I really like the idea of a backup that I can switch on when I really need it :)
I have a Zero S 14.4kWh from 2019. When trying to drive the battery to its last drop, I noticed that I was able to drive about 20km, at 30km/h when the gauge first showed 0%.
Since I have it, I’m assuming everyone has it? This sounds like a software update giving you a "limp home" battery.
I don't think a carriable limp home battery is really doable.
Let us first determine the amount of power that we need to limp home;
- Our system works from 96v – 116v with a average of 102v. This means that we would need a “limp home” battery setup that has the same voltage.
- Driving 30km/h will use about 20Wh/km? (just a guess) which is about 20/102 = 0.19Ah/km.
- If we want to drive 20 km, we need 0.19*20 = 3.9Ah storage. (let’s say, 4 to 5Ah)
Actually, this does not seem impossible.
We need about 14 of the following batteries, placed in series. Then we can travel about 26km
(https://cdn-global-hk.hobbyking.com/media/catalog/product/cache/1/image/660x415/17f82f742ffe127f42dca9de82fb58b1/2/0/209467.jpg)
* Take note, we would need to connect this to the motor controller and ensure that we don't kill the original battery and stuff. (this is the disclaimer to only do this when you know what you are doing)
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I think this would be very difficult to setup without much lower level firmware access to the bike.
Connecting a full battery made of those to the bike's aux port with a depleted battery would cause a massive inrush current into the depleted main battery, most likely far more than the discharge rating of the small battery. Causing fire. battery damage, or worse,
The only way to do this is to have the original battery's contactor open. Trouble there is that the MBB and BMS communicate, and the bike will know the battery contactor is open and prevent the bike from running. Current consumption and other data is also passed to the MBB. So you'd have to create a BMS that fools the MBB into thinking everything's fine.
To me, you're describing a smaller powertank, and Zero specifically only allows those to both connect if they are both almost equivalent voltage, due to this risk. The newer FST platform bikes and SR bikes will run on the powertank alone for a limited range and power though.
So to do this safely, you'd need to build the battery pack, spoof a BMS, and either only connect it with the main battery contactor open or add a contactor.
Or hope Zero decides to build something like that as an accessory :)
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I had envisioned a much simpler solution than that, with no intention of running the bike's motor off the backup battery or connecting it directly to the main battery. I just want something I can hook up to a charger (probably a DigiNow SC since those can accept DC input) and feed it 32A @ 116 vdc until the main battery has the extra mile or two I need to make it to a charger. 28 Molicell 45A 21700 cells in series should do the trick.
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Ah yeah, much more doable. :P The onboard charger or a diginow will probably take dc in. In your case the tricky part might be getting a consistent voltage across the battery pack discharge curve.
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I had envisioned a much simpler solution than that, with no intention of running the bike's motor off the backup battery or connecting it directly to the main battery. I just want something I can hook up to a charger (probably a DigiNow SC since those can accept DC input) and feed it 32A @ 116 vdc until the main battery has the extra mile or two I need to make it to a charger. 28 Molicell 45A 21700 cells in series should do the trick.
I don't believe the bike BMS will allow you to charge and ride at the same time. That means (unless you want to be parked on the shoulder while adding your limp-home-charge) you will need to spend some time in a parking lot, so you might as well spend it next to a proper charger. .
I think this would be very difficult to setup without much lower level firmware access to the bike.
Connecting a full battery made of those to the bike's aux port with a depleted battery would cause a massive inrush current into the depleted main battery, most likely far more than the discharge rating of the small battery. Causing fire. battery damage, or worse,
The only way to do this is to have the original battery's contactor open. Trouble there is that the MBB and BMS communicate, and the bike will know the battery contactor is open and prevent the bike from running. Current consumption and other data is also passed to the MBB. So you'd have to create a BMS that fools the MBB into thinking everything's fine.
To me, you're describing a smaller powertank, and Zero specifically only allows those to both connect if they are both almost equivalent voltage, due to this risk. The newer FST platform bikes and SR bikes will run on the powertank alone for a limited range and power though.
So to do this safely, you'd need to build the battery pack, spoof a BMS, and either only connect it with the main battery contactor open or add a contactor.
Or hope Zero decides to build something like that as an accessory :)
The inrush of current can be limited with a simple circuit. Charging resistance of a battery (even when nearly empty ) is quite high so current limitation might not be needed. If I remember correctly, charging resistance has already started to increase considerably when state of charge drops below the last 25%. The real numbers are dependent on the actual battery chemistry though.
In short, I don't see a way to add a usable reserve battery without voiding the warranty.
I think Zero would be wise to add an 10% "reserve", maybe as an selectable option. The dash might flash "You are now on reserve energy, head directly to the nearest charging point.". I believe it would have many benefits. Reduce range anxiety without reducing real range.
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I had envisioned a much simpler solution than that, with no intention of running the bike's motor off the backup battery or connecting it directly to the main battery. I just want something I can hook up to a charger (probably a DigiNow SC since those can accept DC input) and feed it 32A @ 116 vdc until the main battery has the extra mile or two I need to make it to a charger. 28 Molicell 45A 21700 cells in series should do the trick.
I don't believe the bike BMS will allow you to charge and ride at the same time. That means (unless you want to be parked on the shoulder while adding your limp-home-charge) you will need to spend some time in a parking lot, so you might as well spend it next to a proper charger. .
OK, good to know! Still, if worst comes to worst I’d rather spend an hour on the side of the road charging from a bailout battery than four hours waiting for a $125 tow truck. In these scenarios, I already tried to make it to a proper charger and failed.
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Do you have any friends/family who could simply bring you a small generator and then charge your battery for a few minutes that way? I mean, how often do you plan on tempting fate by driving to 0% ?
There is also this company if you live in CA.
https://www.greencarreports.com/news/1128138_sparkcharge-mobile-charging-will-get-tested-by-roadside-assistance-in-sf-and-la (https://www.greencarreports.com/news/1128138_sparkcharge-mobile-charging-will-get-tested-by-roadside-assistance-in-sf-and-la)