This Schumacher Instant Portable Power Source has an on/off switch that activates the jump start mode. A built-in charger for automatic charging of the internal battery; just connect an extension cord to the plug to recharge (cord not included). The battery status LEDs tell when a battery is charged or needs to be charged. The Sure-Grip Clamps fit both top and side-mount batteries. The cable will stay flexible in the coldest weather. A maintenance-free, sealed lead acid battery allow for storage in any position.