I have a bunch of quite old Lithium Ion 18650 cells salvaged from laptop batteries over the years, they are all in good condition as far as I know.
I no longer need them so I want to take them to the local recycling centre. Having them stored in my garage is making me nervous as they might pose a fire hazard (
).
They are all charged (to about 4.0 V) and I think it's probably best to discharge them before I have them recycled.
I'm looking for guidance and perhaps a few good ideas about how I can responsibly dispose of these while not wasting all that stored energy!
The cells are all individuals, not ganged together in packs any more.
Question 1:
I reckon there's at least 300 Watt Hours of power in this collection. Are there any ways I can somehow "
decant" the energy from these cells into a single large cell or battery (perhaps a 12V one, that would be nice!)?
I'd be happy with doing this one 18650 cell at a time, I'm in no rush. Is there something I can buy (inexpensively) off-the-shelf that can do this? If not I'd be willing to build a circuit if one exists.
Question 2:
How low a voltage should a Lithium Ion 18650 cell be discharged in order to a) recover the most energy from it, and b) make it
safest for the people doing the recycling?
The cells have been well cared for and never over- or under-charged.
What would you guys do in this situation?