PowerTank LithiumPortable power pack for your computerized Celestron telescope using Lithium Iron Phosphate (LiFePO4) chemistry Smaller, lighter, safer, and easier to maintain than lithium ion and sealed lead acid designs Up to 2000 charge cycles four times more than lithium ion and 7 times more than sealed lead acid designs Un recharged shelf life of up to 10 years 3 times better than lithium ion and 10 times better than sealed lead acid designs Environmentally