What is “self- discharge“ in Li-Ion battery
Aug ,2010

It means that a Battery loses its power or energy gradually when it is being stored and not in use for some time. Therefore, battery needs to be re-charged before tool can be used.  As Li-Ion battery self-discharges at only 3%-10% per month, battery tools with Li-Ion batteries always get ready sooner for operation and its low discharge rate sustains busy productions better than Nickel based batteries.