We recommend that you fully charge the battery before first use.  To charge, connect the adapter to the charging port and plug the battery into the charging port. The LED lights illuminate to show battery level and indicate active charging. Red meaning charging and Green meaning fully charged.

The LED lights will remain illuminated when fully charged while adapter is plugged in. The battery may be recharged at any time and at any battery level. However, it is not recommended to fully deplete the battery level. Recharge the unit regularly to best prolong battery life. The average run-time is 1 hour at the highest intensity setting, and longer at lower levels. 

Do not leave the charger plugged in after the battery has been fully charged as this may lead to reduction of useful life and/or damage to the battery.

Make sure the charging unit is unplugged from the Pro before using.  When not in use, unplug the charger from the outlet and make sure the cord is easily visible so that it won't be stepped on or subjected to damage or stress.  The charger should be used indoors, in a well ventilated, dry location.  Charging outdoors near any location that has the potential of becoming a wet surface, or one that exposes the charger to moisture, rain or snow must be avoided.  Do not use the battery or charger in the presence of potentially flammable materials as this could generate a fire.