A battery charge system including an adapter node, a system node, a battery, a first isolation switch coupled between the adapter and system nodes, a second isolation switch coupled between the battery and system nodes, a boost converter, and a controller. The controller turns off the first isolation switch and turns on the second isolation switch during a battery mode, activates the boost converter when an adapter voltage is detected, turns off the second isolation switch when the system voltage rises above the battery voltage, and turns on the first isolation switch when the system voltage rises to an operating voltage level. The boost converter may then be turned off once in the adapter mode. The second isolation switch may initially be turned on partially at a low current level when the adapter is detected, and then turned fully on when the system voltage is at the operating voltage level.