Just leave it in your trunk and its ready to charge your car when you need it. 100 seconds quick charge. 300amp starting current. Maintenance free , no need to charge during storage. Shelf life - more than 10 years. Instantly start vehicle with a weak battery mounted(5% residue or more) Pre-charge mode to start engine without any battery mounted. No degradation of performance with freezing temperature. No degradation of performance with age. 10000 times jumpstarts.