Chalo
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The Chrysler battery almost fits!
Maybe I can "shoehorn" it in? Does it have a BMS?
If it does, it's proprietary. Plan on adding your own or managing by other means.
The Chrysler battery almost fits!
Maybe I can "shoehorn" it in? Does it have a BMS?
Any threads where people have bought these batteries and what they’re doing with them? Are they just harvesting the cells?If it does, it's proprietary. Plan on adding your own or managing by other means.
This one use prismatic cells. Are those safer with fire concerns?None of those specify brand name cells like Samsung or LG, so I wouldn't touch them. Fire risk too high. If I had to deal with one of those 4, I'd take the second, since it's NMC and tougher to catch on fire
There was someone on this forum who build custom batteries with A123 LiFePo4 prismatic cells. He turned me down on a request for a custom build, says he's too busy. I am willing but not sure about the capable part since I've never built an ebike battery before. I would consider giving it a try. I have a good background in electronics (been a hobby of mine for many years). I prefer soldering or screw/nut connections, not welding. Will that work?I'm sorry I can't access aliexpress so can't say if the ones you posted are good or not.
What I suggest it that you try to search for automotive grade cells if possible. Meaning cells that are used in actual EV cars.
The reason is that they are likely to last vastly longer and provide better perfomance overall.
I'm using A123 cells on all my builds and I can definitely say they are fantastic, but they might not be easy to source wherever you live so I don't know if this is an option.
That being said, your scooter is low powered so you don't really need such high spec, high discharge cells. In my opinion you could be fine with some random LiFePO4 prismatic cells .
as long as you don't increase power later
Are you willing/capable to build your own battery yourself? Do you feel confident you can wire and program the BMS yourself?
If not, maybe try to look for someone who builds batteries in the classifieds of this forum, hopefully there might be someone in your country who does this.
While that is absolutely correct, remember that his scooter originally came with a lead acid battery.LiFePo batteries, while durable and reliable, are also about twice as heavy for a given energy density. So, IMO, not particularly ideal for a motorbike or ebike.
LiFePO4 also has a flatter discharge curve than some other Lithium Ion cell chemistries.The main difference to account for here, at least in my opinion, is the cell expected lifespan, which is typically way longer for this type of chemistry. Meaning his battery should last a whole lot longer, tolerate deep discharges a bit better and be generally safer to use. This is why LiFePO4 is arguably a better option in this particular case.
While that is absolutely correct, remember that his scooter originally came with a lead acid battery.
So if he replaces it with a LiFePO4 one he'll get about half the size and half the weight for the same capacity. He seems like he was fine with the original range and the scooter doesn't need a ton of power since he didn't talk about upgrading the controller or the motor.
The main difference to account for here, at least in my opinion, is the cell expected lifespan, which is typically way longer for this type of chemistry. Meaning his battery should last a whole lot longer, tolerate deep discharges a bit better and be generally safer to use. This is why LiFePO4 is arguably a better option in this particular case.
Well yes and no.And if he uses lithium Ion, he could reduce the weight to a fourth - or alternatively, have twice the stored power as the LiFePO4. One of the best ways to increase the lifespan of lithium ion is to avoid deep discharge and high rate (per cell) discharge. So the advantage LiFePO4 has is reduced as you use more and more lithium ion cells in parallel.
All good points. I guess it comes down to priorities and expected life of the device. If longevity and safety/stability are the priority, then LiFePO4. If range and/or weight are your priorities, then Lithium Ion.Well yes and no.
While everything you say is correct, the typical lifespan of an NCM battery is somewhere around 500-1500 cycles. The typical cycle of a LiFePO4 cell is 3000 to 6000 cycles. Sure he could double or even quadruple the capacity, but this would also double or quadruple the cost. And it wouldn't double or quadruple the lifespan, as most of the ride isn't done at high C-rates.
Also, LifePO4 cells tends to tolerate higher discharge rates without being damaged.
Last but not least, cells will degrade with time, even while sitting doing nothing. This effect is far less pronounced with LiFePO4.
The only way I'd recommend him to go for NCM cells in this application was if he planned on having the most possible range.
Yes, exactly.If longevity and safety/stability are the priority, then LiFePO4. If range and/or weight are your priorities, then Lithium Ion.
Yes, tha'ts a good point, not many manufacturers offer this chemistry anymore. I suppose it's because it is less advantageous in terms of ratio capacity/price. But thats just my guess I don't know.It is interesting to note that the maker of this particular motor bike offers two options, Lead Acid and Lithium Ion. No LiFePO4 is offered.
My ebike with Li-Ion batteries was still doing fine after more than five years of riding and somewhere between 15,000 and 20,000 miles on it.
Unfortunately not many companies put long term reliability on top of their priority list nowadays.
Why are you entering 30Wh as total stored energy target? Luckily even the smallest pack stores 500 Wh, but at peak power of 1500 W that's just 20 minutes of run time.
Probably brain fart.Why are you entering 30Wh as total stored energy target?
I've had my 60V controller apart and the electrolytic capacitors in it are rated to 100V. Is that enough for it to run on 70 V? That Super Beast looks like a better deal. Which BMS and battery charger do you recommend for 20s2P?go 20s The headway cells rest around 3.4V/cell that is 68V charge to 3.45V-3.5V/cell that is 69V-70V fresh off the charger. Can your controller handle 70V? Doubtful it would be 70V for long once you turn the scooter on. https://batteryhookup.com/products/1-low-row-super-beast-headway-24v-48ah-1-23kwh would be cheaper per cells plus you would have extras. a 20s1p would be a .512 kWh battery go 20s2p and you have a 1.24kWh battery pack.
Either BHU calculater is broke or I am not reading it right. max continuous discharge should be the max continuous discharge of the cells in parallel. 120A which is probably >100A based on the headway super beast I harvested headway cells from.
Max Continuous Discharge Current: 31.58A << should be higher, the headway cells are rated at 120A max continuous discharge.
Later floyd
These cells could work, of course, but they have a very low capacity. Meaning with only 8Ah you won't go very far before they will be discharged. I suggest you put more of them in parallel if you want to be able to do more than just 10km.I've been trying to sell the Fly 7 moped with no battery for $300 (I paid $1,000) but no takers so far. How about these used Head way LiFePo4's https://batteryhookup.com/products/...2v-8ah-lifepo4-battery?variant=39838570741922. What do you think? Are they suitable? I like that they need no welding and come with screw terminals.
I put 60V in their calculator and it recommended 19S1P.
I want to build the pack to fit inside this case from the 60V lead acid battery https://endless-sphere.com/sphere/attachments/img_3197-jpeg.347179/
Can you recommend a BMS? How should I wire them up? Bus bars or wire with lugs? Any suggestions on how to build the pack into the case that's safe and won't fall apart?
Should I buy a few extra cells in case some of them are no good? If so, how many?
View attachment 360095
Unfortunately these won't fit in the space where the lead acid battery was. There's a space for another battery under the seat which is smaller so it won't fit there either.Can you fit these in your scooter? https://batteryhookup.com/products/2s-leaf-modules-7-6v-44ah
for 60V you would need to parallel 8 or 9 of them, so 8s1P or 9S1P
These are good, reliable automotive grade cells with screw terminals, should be perfect for you if you can manage to get them to fit in the frame.