Battery type and starting question

[tractoman]

My boat has 1 Costco Deep Cycle, I think group 24 size. When I start the boat after not running for awhile (days), it takes a little while to get started. I normally shift it into neutral, and open the throttle up full once or twice, and then leave it just above idle, then crank it for 3-5 seconds and if it doesn't start, turn the key off, wait a couple seconds and crank again for 3-5 seconds. It normally starts after a couple tries. My question is, is a deep cycle the correct battery for the boat to start it? I've read that there are marine starting batteries, are they different from deep cycles? Once the boat is warmed up, it always starts in about a half revolution of the engine, so it seems cold blooded, and I want to correct this. I have not yet checked the choke setting and I always charge the battery full the day before going out.
Thanks,

 

[trendsetter240]

Re: Battery type and starting question

Marine starting batteries are designed to deliver a very high current for a short amount of time. Deep cycle batteries are designed to be discharged at a lower current for a longer period of time.

Deep cycle should be used for onboard electronics, electric trolling motors etc.

You can use a deep cycle battery to start your motor, it won't hurt anything, it will simply have less cranking power. There should be a rating for CCA (Cold Cranking Amps) or MCA (Marine Cranking Amps) on the battery. If your engine sounds like it is laboring when youre cranking it over look at getting a starting battery with a higher CCA or MCA rating. I use a 1000MCA starting battery in my boat.

If you use a lot of power for onboard electronics then you can get a battery isolator that will allow you to hook up both a starting battery and a deep cycle battery. There are posts here showing how that is done.