Instruct: Classify a review as either positive or negative.
Query: Essential gadget for large electronic Telescopes

I used my Power Tank (17Amp version) for a whole year. After many months of bad weather, I stored it away with my Telescope. Six months of unattended storage were enough to kill the battery. I should had read the manual before putting it away for so long. These tanks need to be recharged at least once a month in order to preserve the cell inside. These power tanks contain a sealed dry 12Volt battery cell inside. One can probably replace it, but it in my case, the cost for the 17amp version is roughly $40 plus the risk of installation. I decided to get a new Power Tank 7Amp version because it is more than enough for my Telescope (Meade LX200GPS). In conclusion, the power tank is a must have for large 12Vdc telescopes, but one must take very good care of charging it at least once a month in order to get maximum lifetime of the product.