Unsafe EV batteries end up in e-bikes as China battles illegal chop shops

[Redaktion]

A new '"One Bike, One Battery, One Charger, One Code" policy cracks down on illegal EV battery disassembly shops that present an e-bike fire hazard. E-bike manufacturers are mandated to continue support for their current products and provide spare parts for at least five years.

https://www.notebookcheck.net/Unsafe-EV-batteries-end-up-in-e-bikes-as-China-battles-illegal-chop-shops.1325186.0.html

[Tank3]

Every year gets more and more wild. Now bike accidents are going to result in Pinto-style explosions

[voltage != capacity]

The national standard for electric bicycle batteries caps them at a 48 V voltage, a limit suitable for densely populated urban areas given the typical casual treatment of batteries by e-bike owners or renters. The repurposed EV cells, however, often blow past that ceiling to be offered by e-bike makers as "ultra-long range" models

Voltage doesn't matter for range, it's the Wh. They could simply connect them in parallel and stay at 48 V.

I remember a video of a guy (I think it was somewhere in asia, CN possible) with a, presumably, bike battery in this hand going into an elevator and just before the door closed, the battery exploded.

[Srumo]

When I lived in China, I learned that when people can cheat to make money, they will most often do it. It is cultural. So this is not surprising. At least this is not as bad as milk powder.

[anan]

Voltage doesn't matter for range, it's the Wh. They could simply connect them in parallel and stay at 48 V.

I remember a video of a guy (I think it was somewhere in asia, CN possible) with a, presumably, bike battery in this hand going into an elevator and just before the door closed, the battery exploded.

The crux of the "ultra-long range" moniker is not that it relates to range. It masks the fact that it has a higher voltage pack. Basically - long range needs a bigger pack. A bigger pack technically can have higher voltage depending on cell arrangement.
All of this allows them to sell bikes that are easily modifiable to run on higher voltage and make more power to the wheels.
And the more power you try to draw the more likely you will get a thermal runaway event.

[Wang Hung]

Voltage doesn't matter for range, it's the Wh. They could simply connect them in parallel and stay at 48 V.

I remember a video of a guy (I think it was somewhere in asia, CN possible) with a, presumably, bike battery in this hand going into an elevator and just before the door closed, the battery exploded.

The crux of the "ultra-long range" moniker is not that it relates to range. It masks the fact that it has a higher voltage pack. Basically - long range needs a bigger pack. A bigger pack technically can have higher voltage depending on cell arrangement.
All of this allows them to sell bikes that are easily modifiable to run on higher voltage and make more power to the wheels.
And the more power you try to draw the more likely you will get a thermal runaway event.

Actually more voltage by arranging cells in series results in lower overall current draw from each cell. This usually leads to cooler-running but also slower-charging battery packs.

There are other causes of battery combustion. Like cell quality, the more cells you have the more likely that one or more of them will break down during service life. Packing poor quality cells together like the chop shops is a recipe for disaster statistically. Bike frames are also less protected from shock and thermal cycling, making cells degrade faster in this environment. Then there are seal failures letting in moisture or just exhalation due to pressure and temperature changes. EVs after major flooding events are prime examples of this. I doubt the bike seals are better than those of EVs, because neither are designed to be submerged or exposed to water extensively. Anywhere that does this kind of chop shop stuff would also likely sell knockoff chargers, which also can cause fires.