How many CCA for starting battery?

[quick]

Costco has them on the cheap side, but they only have 550 or 650 cca. The battery in my boat is like 800. Should I just go somewhere else or would either of these work to start my boat?

The boat is a 2002 20i.

Thanks,

Quick

[chpthril]

As things age, resistance goes up, which equals less current flow (through wires and connectors), lower voltage and higher current draw from things like starter motors. Rule of thumb is to actually go up in CCA's for a replacement.

[quick]

so these will not work then?

Thanks for the quick response.

[chpthril]

so these will not work then?

Thanks for the quick response.

They would probably work fine, What I posted were recommendations based on experience and Ohm's law. it never hurts to have a little reserve.

[quick]

Thanks again for all of your help!

[quick]

They had an optima blue top that was 750 cca so I went with that. It appears to work fine.....a little more costly, but the interstate batteries there were only 600 cca, and not 650 like I had thought.

[chpthril]

They had an optima blue top that was 750 cca so I went with that. It appears to work fine.....a little more costly, but the interstate batteries there were only 600 cca, and not 650 like I had thought.

Just watch that the alternator doesn't leave that battery undercharged. That is a common occurrence with those gel-cells as they seem to require a bit more voltage to recharge then what a typical wet-cell does.

[jsz]

I've got 2 costco batteries and they have worked well for years. When I got them I kind of remember them having higher CCA's (around 700) then the others I was looking at and they were cheaper. I did not compare them to Optima.