Overniter Question on Battery Placement

Designs for inboard or outboard power

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Overniter Question on Battery Placement

Postby indyillini » Tue Jun 13, 2017 6:18 pm

I am finally at the point of wiring my boat for launch later in the summer. I am really wrestling with my battery placement. I have determined that I need a two battery system. My boat is the 16ft overniter and I have a 2015 Mercury 90HP 4 stroke and a 16 gallon fuel tank in the back as well. My question is should I put the batteries in in the back as the boat was designed or put them in the front at around the 10 foot point from the transom? I was also considering putting the cranking battery near the motor and the house battery near the 10 foot point. I am using series 24 batteries so they both weigh around 45lbs each. Any advice would be appreciated. Thanks.

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Re: Overniter Question on Battery Placement

Postby raymacke » Wed Jun 14, 2017 9:35 pm

If it were me, I would place the starting battery at the transom. The closer to the O/B the better to keep the heavy cables as short as possible. Most outboards come with cables long enough to to this. A more forward location may require additional cable and connections capable of handling the load which also induces somewhat of a voltage drop. Closer is better.

I would locate the "house" battery more forward for a couple reasons. First, more than likely most of the wiring attached to it will be forward. Again shorter wire runs are better for voltage and cost savings. Next is weight at the transom. Particularly, with smaller boats adding extra weight at the transom can hamper getting up on plane. Of course, a 16' boat being pushed by a 90hp shouldn't have much of a problem there but not sure how the weight of a modern 90hp 4 stroke compares to the 2 strokes of the day when this design was created. No matter, I think the forward location of the battery and accompanying fuse panel would make sense.

Just my thoughts!
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