[ecomodded]

Ni-cads do well laying dead for months even years at a time, Lithium not so much. Lithium does not like to sit fully charged, it wears the battery out if you let it self discharge from full, you should half discharge them before you store them.
Lithium are highly voltage sensitive, do not overcharge them by even 1 volt, a 1 volt over charge would damage and kill them. Always use the approved charger..
Never drain lithium batteries, you can double or triple their recharge cycle count by not draining, mind you, you may burn threw the cycles slightly faster.