Does leaving a battery in a charger after fullt charged damage the battery?

Yes and no. Yes it will damage the life and rechargeability of the battery if its a normal streight through charger. No- if your battery charger has a trinkle charge on it. Trinkle charging is when a battery is fully charged and the charger recognizes this and stops charging and allows the battery to loose some charge and then repeat the process, instead of continuosly shoving power into the battery. Some chargers and most new chargers have this feature built in. And some will say this on the charger itself. But the majority of chargers do not have this feature and you should take the battery off and either let it sit or use the battery until its almost or better yet all the way dead. That is the best way to keep your battery memory fresh and make it last. BIGJ