Keep the Wagan battery jumper with air compressor on hand to handle roadside emergencies. It has a 900-amp jump starter to let you start up your vehicle"s battery. It also has a work light for security while connecting wires. The air pump can be used to fill up tires in minutes. This jumper even has a USB port that allows you to power up your music player, cell phone and much more. You can charge this portable battery jumper on the go via your car"s lighter socket with the DC adapter that"s included. It takes about 38 hours on AC power and 12 hours on DC power to fully charge it. An indicator light lets you know the remaining battery power in the unit. This Wagan 900-amp battery jumper has overload and short circuit protection for added peace of mind.