All purpose battery?

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ganman
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All purpose battery?

Post by ganman »

I have always had a cranking battery and deep cycle(s) on my big boats but I'm picking up a John boat for small waters. Here's the thing. I want electric start and trolling motor but I don't want to go with 2 batteries because of weight and space. Is it possible? The OB will be a 15HP and the electric a 36 lbs. I plan on running a portable sonar.
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scarkner
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Re: All purpose battery?

Post by scarkner »

You don't need a cranking battery for the 15hp. In fact, I haven't used a "cranking battery" in any boat for years. The main focus of cranking batteries in boats is simply separation of the power so the trolling motor doesn't suck you down so low that you can't start the main engine. But you could use two deep-cycle batteries in a boat no problem. For cars and trucks it's a different story since you need to start at cold temperatures so you want a "cranking" rated battery purely for the Cold crank ability.

I have a 2004 electric start 15hp mercury. I can start it with just about anything (last year I used a 4Ah lead-acid gel cell out of one of those emergency lights that mounts on a wall). But since the 15hp has a built in pull-start (I assume yours does too) the concerns about not having enough energy to crank the motor is kinda moot. You can always start it easily with just a pull.

So go with just one deep cycle battery, nice and small, just for your trolling motor. Your 15hp will start just fine off it.
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ganman
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Re: All purpose battery?

Post by ganman »

Thanks,

I have a bad shoulder hence the electric. With the weight of the 4 stroke, me and two batteries it would be a lot of weight.
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reid
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Re: All purpose battery?

Post by reid »

I have a 20 hp Nissan and a 36 thrust trolling motor and hummingbird and just use one battery. The motor charges the battery and I am good for two weeks. I would like to get a solar panel charger for it.
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PunchRig
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Re: All purpose battery?

Post by PunchRig »

just spend the xtra $$ and buy a good trojan or northstar AGM 27 group,it will run everything all wknd.
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Haybay Larry
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Re: All purpose battery?

Post by Haybay Larry »

Remember that deep cycle batteries are meant to be used and then charged up each time. If you go away for a weekend or longer and use the battery multiple times without charging between uses you will shorten the life of the batteries. A small portable gas generator can be purchased for a couple of hundred dollars and then your regular battery charger from that will ensure maximum life of the batteries.
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