I don’t know how old these are but I’ve been using them (sparingly) for the past couple years in a C3HA/M91BN setup. Lately I’ve noticed that the light will only stay on for a minute or two before quitting- although it does come back on if you cycle the power switch. Right now they are showing about 70% on my charger…
I figure it’s about time to retire these puppies. What’s the go-to for a high reliability 2s li-ion cell in 17500?