Celestron PowerTank Lithium Battery Pack - 18771

Say goodbye to bulky batteries and explore new dark sky sites with your telescope and this ultra-portable lithium battery pack by Celestron. Measuring just 7.5" tall and 3" in diameter, PowerTank Lithium boasts and 84.4 Wh capacity--enough power for up to 10 hours of observation! Lithium ion technology comes to your telescope You already trust lithium batteries to power your mobile device. But Celestron's new LiFeO4 lithium phosphate batteries significantly outperform even traditional lithium ion batteries found in handheld electronics. If you already own a sealed lead acid telescope battery, you know that they have an uncharged shelf life of just 6-9 months. Twice a year, you have to fully drain and recharge the battery to keep it in good working order. Traditional lithium ion batteries do a little better, with a 3 year average shelf life. But PowerTank Lithium boasts a shelf life of 10 years. PowerTank Lithium also blows the competition away when it comes to lifetime charge cycles: 2