I found a box of old (2+ years) 18650 and 18350 batteries from vaping. How do I tell if they are safe to use?
I do have a multi-meter and here are the results:
.25
3.91
4.19
2.76
.11
.17
3.84
3.51
3.84
.15
.79
.22
4.17
Pretty sure I know the ansewer, just double checking
I assume the ones that are below 1 are done and can’t be used anymore? What is the cut off for discharge?
The others will be fine even though they are old?
They are all AW and Efest.
If they are protected, I’ll make a try to put them in a charger, maybe it’s only the protection circuit that tripped. Just putting them in a minute and then check with multimeter.
If are unprotected, I’ll throw away all those under 2.5, batteries are really cheap now, better safe than sorry
They are unprotected. Thanks for the confirmation.
Cheers!
recycle would be better, but not always an easy option depending on your location.
Indeed. I have a special box for battery recycling.
All the unprotected batteries with a lower voltage than 2,5V are to be recycled.
Wouldn’t protected cells that have tripped just show 0v?
To be fair, I, too, recycle mine. Sorry for my bad word choice, I’m not really a good english speaker/writer…
I’m assuming a really bad multimeter from OP 
So maybe it has a high error margin and shows something where it isn’t