SKIL PWRCore 12 12-Volt 4 Amp-Hour Lithium Power Tool BatteryPWRCore 12 volt lithium battery technology wraps each cell with cooling material to keep the battery power on for 25% longer run time and 2X battery life This 4. 0Ah battery has your back on projects that require extra run time Plug into the battery's USB port wherever, whenever with PWRAssist mobile charging Green LEDs on the battery show the charge status, so you always know how much power is left Pair with any SKIL PWRCore 12 product Features