From the Manufacturer
Rescue Pac with 3 amp charger. Quickly recharges your vehicle battery and is a portable 12 volt power supply. Designed to fully discharge its internal battery's power into the vehicle's battery. Works through vehicle's cigarette lighter. No need to open the hood. No messy cables and clamps. Average recharging time is 15 minutes. LED's indicate: When Rescue Pac is charging battery. When Rescue Pac has fully discharged its internal power. Rescue Pac's own power level. Sealed battery won't leak. Can be transported, used or stored in any position. Recharges from any household outlet.