The rcr123a charger pack consists of a usb cable charger and two re chargeable li ion batteries either one or two batteries can be charged at any time this charger pack is used for the spark flash and flare exposure lights the charge time is approximately 4 hours and simply connects to your laptop or desktop computer lithium ion battery care rcr123a and cr123ra batteries should not be used if damaged in any way dropping the batteries can cause internal damage to the cell which may not be