Designed specifically for the unique needs of computerized telescopes, the Celestron PowerTank Lithium LT Power Pack is built with a rechargeable lithium nickel manganese cobalt oxide [Li(NiMnCo)O2] battery that delivers a steady charge over long periods and requires less maintenance than traditional sealed lead-acid batteries. A built-in 12 volt regulated circuit provides your telescope with up to 8 hours of consistent power at the proper voltage for optimum performance, and to keep your other gear like phones, cameras, or handheld GPS units going while you're out observing there is a rapid-charge USB port. Ideally suited for off-the-grid applications, the housing is compact and lightweight so it won't take up a lot of space in your kit. The PowerTank comes with a 6.5-foot telescope power cord and an AC charger.