All portables require a battery to supply power to the unit. If the batteries are charged correctly, the units will provide a longer period of operation. Plus the life of the battery will be increased. It is always best to turn off the radio prior to charging and, when possible, drain the battery prior to charge. Never transmit when the portable is in the charger. Charging the battery using supplied 6- way Bank Charger 1-2 hours should provide from 90-100% battery charge.