Some tool batteries only charge up to 4V per cell or 20V in 5S config, yet they still claim full capacity. Maybe because if they charged all the way up it will take 50% longer in the CV phase and probably degrade the battery when stored full.
The batteries from my Mavic air drone will auto discharge to 3.8V after not being used for a couple days.
Could be just perception but I store batteries with relatively low cycles at 4.2V for months at a time and after a while I notice they don’t stay very long at 4.15V+ after removing from the charger, the capacity however doesn’t drop more than 10% when tested (4.13 vs fresh cycle).
I’ll use the same light.
I am not interested in the empty to full battery capacity, i am interested in how much juice goes in when discharged from 4.2V to 4V and charged up to 4V then charged to 4.2V.