Celestron Car Battery Adapter for All NexStar Telescopes - 18769About the Celestron Car Battery Adapter for All NexStar Telescopes The hobby of amateur astronomy frequently takes the observer away from sources of AC power. After all, we are always in pursuit of the darkest skies possible, and that often means going off the grid. The most common way to power your telescope in these situations is to use a portable 12V battery pack, like the Celestron PowerTank, or to use power from your car''s battery via the