Can a Marine Battery be too big?

The marine battery that came with my 140 hp MercCruiser engine had 600 CCA when I bought the boat used (1986 Sea Ray Seville 19'). About three years ago I replaced that battery with a slightly smaller Sears Marine battery ( I think it had 550 CCA ). The battery holds a charge but I don't think I'm getting enough amps to start the engine every time. Would it be okay to use a marine battery with 625 or 650 CCA's ?

 

Yes. Hope this helps.

 

Buy as large a CCA rating as you can afford. Typically people add various things to their boats such as radios, depth finders, gps and so on and soon that 600 CCA battery is no longer adequate.

 

A big battery can always power small loads. A small battery can't power big loads though. Buy the highest rated battery you can afford, that still fits in your battery box.

 

Did you check all your connections yet, load test the battery, etc. etc.? Or are you just starting to try and figure out what's wrong?

 

alternator may be too small

and thus your battery may be undercharged

what kind of charging device do you have ?