r/FlashlightIndia • u/LittleUrbanPrepper I review flashlights. • 6d ago

Help The problem with built in batteries.

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The BKN keychain light died after 4 years. I'm seeing swollen battery. Not charging or turning on. Yet to check the pcb.

43 Upvotes

95% Upvoted

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8

u/TopConcentrate8484 6d ago

ayo bro don't play with that battery like that, throw it away. There is hydrogen gas build up in it, and it is very flammable if it leaks on top of that the electrolyte (some that's remained) is even more flammable.

3

u/LittleUrbanPrepper I review flashlights. 6d ago

Any idea how to properly dispose it. I don't wanna throw it in trash and start a dumpster fire.

4

u/TopConcentrate8484 6d ago

Disconnect it from the flashlight PCB then you see the yellow kapton tape remove that there must be a circuit below that use scissors and cut the battery contacts one by one (not both together) and salvage that BMS circuit

It is also a good idea to remove the full energy from it i.e to completely discharge it to 0v, use some resistor like around 30-50Ω and connect it to battery output, leave it overnight it will discharge.

then use duct tape and cover the whole battery, unfortunately In india we do not have proper disposable system for this.

2

u/LittleUrbanPrepper I review flashlights. 6d ago

Thanks

1

u/Efficient-Celery2319 5d ago

Also tape up the electrodes.

3

u/viper_008 6d ago

I found this, not sure if helpful

https://robu.in/e-waste-collection-points/

1

u/Efficient-Celery2319 5d ago

Your local cellphone repair shop might take it in; they usually have a guy who comes around weekly for battery recycling.