1. It is best to recharge the battery after each usage. There is no memory effect so make it a good practice to recharge the pack after each usage or end of each day if you use the battery daily.
2. Never drain the battery till the protection board shut it down as that will decrease the battery capacity and shorten the life of the battery.
3. The device the battery is installed normally has some kind of low battery warning to tell you the battery is getting low. Ex: like your cell phone battery indicator. You should follow the instruction provided by the device manufacturer on what that is and recharge the battery whenever it is possible to avoid over draining the battery and shorten the battery life.
4. A battery should be fully charged over night or less as that depend on capacity of the battery and charging current. The LED on the charger will turn from RED to Green indicate the battery is fully charged. At this point, you should remove the battery from the charger. Do not leave the charger connect to the battery for more than 8 hours as once the charger detect battery is full, there is no charging current and the charger will actually start draining your battery very slowly.