7 year battery only 4 years old and it went dead as a door nail in 5 months. Heated garage. No battery tender. Put trickle charger on and over night its back to 12.4 volts. In 60 yrs of messing with car batterys never had one drop dead not being my error, was like I left the lights on [didn't] . I put another battery in the car that had been sitting for 1-1/2 years to use the car, started right up. So is the stupid battery trustable? Some kind of internal short? Drop it in Napa's lap to check out/exchange?