Harvesting 18650s from electronics, anything to know?

I have a bunch of power banks and other battery packs with bad charge ports or other charging system issues. I wanted to use those batteries for other things. Is there anything I should know?

Be careful disassembling. Use shallow cuts, plastic tools, and careful prys.

Remove tabs connecting cells by force/pliers. Sand/Dremel any remaining solder metal on ends of significant.

After cells are out, test voltage. If below 2.8v, toss. 3.0v to be safe.

Charge the remaining cells. Pulling off charger. Wait 24 hours. If they've dropped more than 0.2v, toss them.

Find the markings on them and Google them. Find out the max charge and discharge currents rated for the cells. Use the cells. Respect those limits both when charging and use in lights, to not overdo it.

That's about it.

Remember the cells will lack protection, so it's up to you to make sure they don't overdischarge.

Thanks for the great advice! I've already got 10 cells! Looks like they are "lgabb41865" not much info that I can find. Looks like a 4A Max draw though. Still not bad.

JoeRodge said:

Thanks for the great advice! I've already got 10 cells! Looks like they are "lgabb41865" not much info that I can find. Looks like a 4A Max draw though. Still not bad.

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LG B4 cells: http://lygte-info.dk/review/batteries2012/LG 18650 B4 2600mAh (Gray) UK.html

Another important point. If the cells are tabbed, resist the temptation to rip the tab off the bottom unless you are desperate. In some cases ripping off the tab can cause a micropuncture in the rear of the cell casing if you are unlucky. If it is not critical for your application, consider cutting as much of the tab as possible and leaving the rest there. Another way is to carefully (slowly) roll-peel (grab the end and roll it around needle nose pliers) the tab up, leaving small burrs that you can gently sand down.

zipplet said:

Another important point. If the cells are tabbed, resist the temptation to rip the tab off the bottom unless you are desperate.

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This applies mostly to spotwelded tool cells with heavy tabs and heavy spotwelds. The thin stuff usually pulls off easily.