Proper battery for Mercruiser 470 I/O motor - Cold Cranking Amps?

[kevinstan]

Can someone tell me the proper CCA's that I will need for my Mercruiser 470? I cant find anything specific online. Is too much bad? I have seen 845 and 1000 CCA's listed, but is it a good idea to guess and just get one of those? Or does it need to be specific to the engine?

 

[Scott Danforth]

Too much is never bad. You only need about 600 cca. A group 24 would be more than sufficient for a starting battery. However if your going to start adding other loads such as radio, trolling motor, electronics, etc and you only have one battery - get the biggest battery you can fit

 

[H20Rat]

To go along with what scott mentioned, I'd even maybe consider a hybrid or deep cycle as a main starting battery for that boat. A 470 doesn't require much to spin over, but if you have a bunch of things you need to run with the key off, the extra reserve capacity can be nice. I'm running a deep cycle on my 4.3l, starts great all the time and I have lots of extra stereo run-time available.

 

[stonyloam]

Yeah, I am from the "can't have too much battery school". It depends on your setup. If you have a single battery and only have room for a class 24, then go for a starting battery with the higher CCA rating. If you have room for a larger class 27 battery (may just have to change battery tray or box) then a dual purpose battery may be the ticket, especially if you have accessories.