It is well known that Li-Ion batteries should not be deep discharged.
But sometimes they do discharge deeply. Is it OK for the device to remain in such state for a long time (and recharge again only when the device is needed again after a year) or it should be charged back as soon as possible?
In other words, the battery was discharged deeply. Now I need to know the best way to prevent further damage to the battery. Should I recharge it immediately or leave it in a deeply-discharged state until I need it again?
Does deeply discharged battery have higher or lower self-discharge compared to normally charged battery?