Batteries to the Cuddy

Bifmalibu

Well-Known Member
Looking to put the batteries in the cuddy on my current project. I'm struggling to find the correct cable size from battery to main engine. I'm finding myself lost in the cranking amps, voltage loss business. Manual states Min. CCA of 380A and Min. Marine cranking amps of 502A. I'm estimating the cable run to be 12-14' from battery to outboard. Will a #2 AWG cable be enough?
 
If you want the option to boost or crank the engine,
more like 2/0 or 3/0

I used 2/0 arc welding cable when I move my batteries midship
 
Last edited:
Like mentioned above 2/0 would be best. Larger cables don't hinder anything except add a bit of weight. Try to use marine type cables or the copper will turn green in no time. Heat shrink all crimps/solders dont use electrical tape.
 
Last edited:
i see you have a 115 outboard 2 gauge will be more than enough, make sure it is tinned and sealed
 
Just a question... is it safe to have batteries in the cuddy? I once considered moving my batteries forward into a large enclosed fish hold and decided against it after reading about gasses released during the charging process.
 
If your moving it 12-14' that means you need to look at 24-28' of wire. Batteries should be mounted as close to source (alternator) as possible.
Why are you moving the battery?
 
Batteries hate being jarred around or dropped....ever go up in your cuddy in rough water? Worst place to be for your back. I wouldn't put them up there. This is why boat manufacturers keep them closer to the stern.
 
I moved the batteries to the cuddy in my double eagle 18.5. I moved them to push some weight forward to make up for the extra weight of a Yamaha F150 repower. I used 20ft of 2AWG which was called for in the charts based on the current required for the motor. Everything works fine but when batteries get low, it struggles to start. If I did it again, I would probably go a wire size higher.

I love having the batteries out of the stern area though.

The chart posted by noluck is a good start.
 
Thanks all for replying. The goal is to get some weight forward, out of the stern. I have all my gas right back there. I don't have the batteries yet, but I believe the gas generated while charging is a non issue with AGM batteries. Conventional batteries with cells do emit a gas.
 
I would love to put my batteries in the caddy I have a 1802 trophy and only have a single battery because of the weight of two batteries in the stern
 
Batteries tend to be in the stern. Boat mfg.'s tend to calculate center of gravity & place fuel tanks/batteries/whatever where it needs to be to maintain proper center of gravity. Moving batteries that far forward is a MAJOR change to center of gravity. Other negative comments on this are right-on.
 
i ran my old trophy with 300 lbs of concrete in the cuddy. batteries installed in the side walls. one on each side. kept the nose down in the swell nice and way less slapping, the kicker wouldnt get swallowed as badly by a following seas.
 
Batteries tend to be in the stern. Boat mfg.'s tend to calculate center of gravity & place fuel tanks/batteries/whatever where it needs to be to maintain proper center of gravity. Moving batteries that far forward is a MAJOR change to center of gravity. Other negative comments on this are right-on.
When I want a change in c.o.g. I just ask my 250 pound brother-in-law to move. ;) We call him Ballast.
 
Batteries tend to be in the stern. Boat mfg.'s tend to calculate center of gravity & place fuel tanks/batteries/whatever where it needs to be to maintain proper center of gravity. Moving batteries that far forward is a MAJOR change to center of gravity. Other negative comments on this are right-on.

The boat in question is a 1990 Hourston 17' I believe when these hulls were built, they were intended to be ran with a modestly powered 2 stroke. Since then, we have started using heavier 4 stroke outboards and using 100lb plus kicker engines. I'm sure it's fair to say that in general, we add much more weight to our hulls at the stern than what they were originally designed for. My idea of moving the batteries forward would be to compensate for this change to the original design and hopefully produce a more level ride, as opposed to the squat that I am anticipating with a 115hp four stroke, a T8, 24 gallons of fuel and 2 batteries directly in the stern.

Regarding the idea of adding sandbags or concrete blocks to balance trim seems illogical and inefficient to me. Why add weight and decrease economy when a necessary component move could do the same thing, with merely an upgrade to cable thickness?

I do appreciate everybody's input and this is why these forums are so great. It really allows a broad spectrum of idea sharing. Thank you all.
 
i did both after moving the batteries only helped a bit. huge difference in comfort , and how it sat in the water.. yes a small amount of inefficiency, but a what better ride and no more kicker stalling out when trolling in a following sea.
 
Bifmalibu; glad to see you have your thinking cap on. Here is some info for starters:

http://newboatbuilders.com/docs/stability.pdf

With a boat that small you should be able to easily measure fore/aft COG. I believe that most commonly this COG will be about 1/3 the length of the boat from the stern.
I'd recommend looking into what the max HP rating is for your hull. There are stability/handing/safety issues in overpowering a boat; especially a small one.
 
The boat in question is a 1990 Hourston 17' I believe when these hulls were built, they were intended to be ran with a modestly powered 2 stroke. Since then, we have started using heavier 4 stroke outboards and using 100lb plus kicker engines. I'm sure it's fair to say that in general, we add much more weight to our hulls at the stern than what they were originally designed for. My idea of moving the batteries forward would be to compensate for this change to the original design and hopefully produce a more level ride, as opposed to the squat that I am anticipating with a 115hp four stroke, a T8, 24 gallons of fuel and 2 batteries directly in the stern.

Regarding the idea of adding sandbags or concrete blocks to balance trim seems illogical and inefficient to me. Why add weight and decrease economy when a necessary component move could do the same thing, with merely an upgrade to cable thickness?

I do appreciate everybody's input and this is why these forums are so great. It really allows a broad spectrum of idea sharing. Thank you all.
I moved the battery's in my old 94 hourston 172 1 on each side under the sleeper seats and it did help I also ran a 115 4 stroke and a 9.9 and it was pretty aft heavy when I asked bill hourston about it he said too much weight aft on those boats was not good Trim tabs did help
 
I owned a 17 ft Hourston and then a 17ft Double Eagle which I bought new. I had it built with a 20 gallon tank in the floor between the seats...so mid ship. Kept the batteries under the well. The 20 gallons of fuel moved forward made for a level ride. Entry in rough water was fun as the boat would launch, land on its tail and then the rest of the hull would settle in...so kinda of a soft double landing. As far as batteries being up front the jarring can break apart cells and destroy them. I sell many smaller gel cells and have dropped a few when trying to carry to many at a time. One drop often kills them.
 
Back
Top