The two major problems with those cells are that they are huge for their capacity, and they are insanely expensive. The cheapest I saw was about $21 each, I don’t know what you’re paying but that is nuts. If you convert that to price per kwh, that’s around $820/kwh. By comparison the pouch cells I use, and the round cells other people use, come in at around $130-180/kwh and with the price of my packs my customers are paying around 4-500/kwh for a completed battery build. For the price, you’re paying for a pack that will never blow up and can dump high amps. But the fact is, that a cell with a regular chemistry will not only have 4x the capacity in the same space, it will also be able to dump those same high amps because discharge is a function of c-rating multiplied by capacity. So, instead of a 25c rating on an 8ah cell (25x8=200a) I’m using cells rated for ~6c peak on a, let’s say 50ah pack, or 300a peak. As a 36v50ah it would take approximately the same space as that ammo can. How do I know all this? I went with a different 8ah 25c cell for my first pack which was 4x the size it needed to be, and I was paying $200/kwh.
Generally for a well balanced ebike pack, you are looking for something with a 3c continuous discharge rating, scaled up in capacity to the discharge you need, which will end up giving you an actual useful range. Far as peak most cells will easily do double their continuous rating, in peak. Obviously you won’t be seeing more than a few seconds of peak discharge before you reach an uncomfortable top speed or something gets burned. Cells with a 25c rating are for other uses- like drag racing, starter batteries in cars, etc. In fact my car is going to be running a 12v pack built from those pouch style 8ah 25c cells. I built a little 12v24ah 600a rated pack as a jumper, and I’m probably going to build a version double the size. My car runs a ~850cca battery so something rated for 1200a peak would be perfect. These pouches also never blow up like your headways, which makes them perfect for use in a car. I’ve tried to blow them up! They just puff up/rupture and some smoke comes out but they never catch fire unlike regular EV cell chemistries.
Generally for a well balanced ebike pack, you are looking for something with a 3c continuous discharge rating, scaled up in capacity to the discharge you need, which will end up giving you an actual useful range. Far as peak most cells will easily do double their continuous rating, in peak. Obviously you won’t be seeing more than a few seconds of peak discharge before you reach an uncomfortable top speed or something gets burned. Cells with a 25c rating are for other uses- like drag racing, starter batteries in cars, etc. In fact my car is going to be running a 12v pack built from those pouch style 8ah 25c cells. I built a little 12v24ah 600a rated pack as a jumper, and I’m probably going to build a version double the size. My car runs a ~850cca battery so something rated for 1200a peak would be perfect. These pouches also never blow up like your headways, which makes them perfect for use in a car. I’ve tried to blow them up! They just puff up/rupture and some smoke comes out but they never catch fire unlike regular EV cell chemistries.
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