Battery packs on E-bikes

[schmitt trigger]

An acquaintance of mine loaned me an E-bike, and after a week of using it, I am convinced it is the future of transportation.
I already have a regular bike, but a combination of hilly terrain and increasing age has slowed me down. Significantly. The E-bike greatly if not completely, eliminates these issues.

But we are not on a bike forum, but on an EE forum. And what I read here and other forums is that battery packs which are subjected to a significant load, appear not to have the anticipated or promised battery life.

One thing is to replace a pack from a cordless vacuum, another is to replace a much larger (and expensive) E-bike pack.

Does anyone here has experience with E-bike or other light transportation (Segways, etc) battery packs?

[eb4eqa]

Two times, I've tried to replace the cells in e-bike battery packs, two times I failed. BMS boards seem very picky about playing with the cells and they will self-destruct easily, they completely die. And the engine management PCB talks about a lot of things with the pack (not sure how secure that communication is), so you can't simply build a pack and expect it to work on your bike. It is nonetheless interesting and no doubt a future thing that we'll need to master.

Roberto EB4EQA
www.robertobarrios.com

[thm_w]

https://endless-sphere.com/forums/viewforum.php?f=21

If you buy a new bike it should come with a 2yr warranty. Don't ever charge at 0C or less.
If you want a battery that lasts the longest in terms of cycles but is a bit heavier, and quite higher up front cost, can go with LiFePo4.

[schmitt trigger]

You are correct that the battery management module has a lot of interfacing with the individual cells, and very likely with the motor controller as well.

There is another thread in this blog where an individual has attempted to resuscitate, or at least understand, the battery management of a Dyson cordless vacuum.
After a lot of fruitless tasks, it appears to be that once the Battery Manager reaches the conclusion that a cell or cells have degraded, essentially it bricks itself out.

My concern is that the e-bike packs are significantly more expensive.

[NiHaoMike]

Base your battery pack around a few EV battery modules and some sort of open source BMS. Then couple it with one of the open source BLDC inverters out there.