Quote Originally Posted by Joe_Black
Well, your old battery was probably on its last legs but it still sounds as if you have a phantom load somewhere. The Blue Top is the marine flavor of Optima and not ideally suited to an automotive starting role, but will work. The Yellow Top is the automotive version of the marine Blue Top, and with either you should be able to run a light accessory such as OEM audio overnight without worry.

Definitely check your load though to see how much is being drawn with everything off, that may be what caused or helped your conventional battery to fail.

I have the blue top marine batt and it works just fine. The extra posts are awesome for hooking up amps,lights,etc. Why would the blue top not be good for starting a car? Boats start the same way a car does! There was another reason for getting the blue top marine batt for me, IT WAS FREE!! So was the one I put in my brothers car. As far as there being a load , it is possible ,but if the batt was junk That was more likely your problem. shawn