The UR18650 are some of the better ICR type li-ions. They are very prolific in Dell, HP/Compaq machines and some Acer, Panasonic, and Fujitsu machines. They came in 2600 mAh mostly. If they’re down to 2.2 v, its iffy on successfully recovering them unless you basically trickle chargw them at like 100 mAh. And let them rest for a couple days to see how they hold that charge. If they hold over 4.12 volts or so, I’d say success and use them for CDR under 2 amps.
if in good condition those are quite useful in non demanding lights.
i have plenty of these in my homebrew powerwall.
looks like yours might be eol.
common failure mode in those cells is heating up over 4v and failing to terminate.
plenty of info out there about this.
search red sanyo heaters.
if yours exhibit this failure discharge them and recycle.
What is a homebrew powerwall?
a homebrew version of the tesla powerwall.
its a battery for solar storage.
How does it balance cells and charge them since i am assuming they are not matched?
Do you have any links on how to build it?
You Test them for capacity and if you’re really into it for Resistance also —-then you sort them out to where you make a balanced pack — Then you use a BMS
(battery management system) to run you pack in said parameters —— If you build it right they stay fairly balanced
https://secondlifestorage.com/index.php?threads/sanyo-ur18650a-cell-spec…
This guy here does some serious stuff
They are not GAs. GAs are raised flat tops, and as far as I can remember, never used in batt packs.
I used to harvest those same flat tops from a working pack yet heated up extremely hot it nearly ruined my beloved Pila IBC charger back in my early days.
Those red Sanyos are notorious heaters, beware of them, better recycle.
Pila IBC… nostalgia