18650 batteries

Lakeland · 14 Nov 2017 at 21:41

So I decided to take apart a laptop battery pack from an 8ish yr old laptop that’s not been used in the last 4 or 5 years..

They were crumbling at the edges and when I checked their voltage they were sitting at roughly 0.2v each

What’s the changes that this was about to become dangerous to have lying around in a cupboard?

adolf hamster · 14 Nov 2017 at 22:53

Much less than the chances of them becoming dangerous because you messed around and broke open the pack

Lakeland · 14 Nov 2017 at 22:56

How’d you work that out without knowing how I disassembled the pack?

rubberduck · 14 Nov 2017 at 23:05

Can you post pictures of the cupboard please?

adolf hamster · 14 Nov 2017 at 23:05

Lakeland said:
How’d you work that out without knowing how I disassembled the pack?

Because those packs are a pita to dissassemble, at least any of the ones i've tried were

Glaucus · 14 Nov 2017 at 23:09

pretty much zero, and as above they are a nightmare to disasnble.

Lakeland · 14 Nov 2017 at 23:19

There were two sticky labels on the enclosure, once peeled off I cracked a bit of plastic off each end then just removed some short pieces of tape and trimmed the metal strips that joined each battery, probably only took 2 or 3 mins tops.

Maybe I got lucky.. I was hoping to salvage the batteries for a project but now they’re outside waiting to be disposed of.

Lakeland · 14 Nov 2017 at 23:21

rubberduck said:
Can you post pictures of the cupboard please?

I’ll wait until the fire dies down before I take any pics.

Rroff · 14 Nov 2017 at 23:29

adolf hamster said:
Because those packs are a pita to dissassemble, at least any of the ones i've tried were

Been 50/50 in my case - the last two one just popped open after going around the edge with a screwdriver - the other I literally was tearing the case apart cm by cm with a knife and pliers LOL and managed to scratch one battery in a way that meant it had to be disposed of and shorted another when I cut through the connection to the control board not realising I'd made contact with the metal casing which was connected to the negative side.

Had one recently which hadn't been touched in about 6 years and the voltage level was around 0.1-0.4v - tried charging them and two just got really hot and voltage didn't rise above 1v, 2 of them charged OK but within a week weren't holding their capacity and the other two weren't holding their capacity at all.

adolf hamster · 15 Nov 2017 at 01:18

Rroff said:
Been 50/50 in my case - the last two one just popped open after going around the edge with a screwdriver - the other I literally was tearing the case apart cm by cm with a knife and pliers LOL and managed to scratch one battery in a way that meant it had to be disposed of and shorted another when I cut through the connection to the control board not realising I'd made contact with the metal casing which was connected to the negative side.

Had one recently which hadn't been touched in about 6 years and the voltage level was around 0.1-0.4v - tried charging them and two just got really hot and voltage didn't rise above 1v, 2 of them charged OK but within a week weren't holding their capacity and the other two weren't holding their capacity at all.

Guess i've just been unlucky then, in fairness i wasnt being particularly focused on preserving the batteries for anything useful it was more just random fiddling cos i was bored.

Rroff · 15 Nov 2017 at 01:27

I've built a few DIY powerbanks, etc. and latest project was prototyping a USB powerbank with UPS and power management functionality. Mostly just out of interest.