8 month old 6V battery dead

[rotorwrench]

Sulfation kills a lot of batteries. The crystals will get larger and harder the longer a battery stays dormant. A person has to draw some current out to clean the plates and then recharge it on a regular basis or its life will be a short one. Some battery tenders do this but they can also have longevity problems and can ruin a battery if they go bad and over charge or over draw.