I'd love this kind of innovation for power tools... The price of a Milwaukee M28 battery is bonkers these days. The cheap Chinese replacements are hit or miss... some come doa and Amazon complains they will terminate your account if you return too many of them.

Isn't there problems with replacing a single cell causing the battery management system to go whacky? I was under the impression that the cells need to be balanced with each other in some fashion.

Replacing single cells is a problem for other cells in parallel with it, especially with the high current of e-bike batteries, but replacing all cells in parallel (appears to be 4 cells in this battery) should be fine. Either way, being able to replace all the cells at once (worst case) is a pretty big advantage too.

You'll just get less capacity if the cells aren't perfectly balanced, which is fine if you're aware of it- and much better than a useless pack.

That said, they don't specifically show/call out replacing an individual cell.

You'll just get less capacity if BMS was wired to monitor individual cells and reported capacity based on that. If you were just measuring voltages at the bus bar, you could over-drain or otherwise over-strain the outlier cell and set it on fire.

Which don't happen often enough to make Amazon do something about fake packs for drills and Dyson vacuums, but I think the chance increases as cell count increases and idiot-proofness decreases.

The replacement process would be almost the same.

Battery cost + density is getting better so quickly the idea of a "BIFL" battery seems silly to me.

I don't think you actually learned what their product is. It enables an e-bike owner to much more easily replace their batteries with newer batteries (the issue of mix-and-match seems like a problem with this however). They aren't trying to sell you a single battery that lasts forever. Instead it is an enclosure that enables you to much more easily service your battery / replace batteries.

Well, article title implies single battery (and not parts of it being replaced regularly) that lasts lifetime. With current technology the only way to achieve that it it to make it explode rather violently. In all seriousness, the issue with that battery's approach is only if it can fit any specific bike, otherwise idea is good since 18650 batteries are highy standardized. except new chemistry right around corner, and new chemistry means different voltages etc

A battery is just a group of cells. You have to replace one or more of the cells eventually, but it is technically a battery that lasts forever. kind of a ship of theseus situation

Sadly no support for the Bosch system.

Are you sure? That's one of the brands that appears in the "compatible with 90% of bikes" rotating gif.

It's also explicitly listed in their documentation: https://docs.gouach.com/knowledge-base/frequently-asked-ques...