Assault and Batteries
- Thread starter rblevens
- Start date
The original battery setup was two group 24 or 27 batteries in the narrow spot between the icebox and the engine (more or less directly below the red main battery switch location). This is a tough spot to work, either hooking up the battery leads or checking the electrolyte (assuming lead-acid batteries). If you are starting fresh, I would suggest under the cabin sole is the best location. I glassed in a shelf there, just aft of where the shower sump is, and have three GP 24 deep discharge batteries there - my house bank. I left one GP 27 as a 'starter battery' in the old location by the icebox. Normally I use the house bank for starting too. The starter battery is my back up.
Several owners have put 6 volt golf cart batteries under the cabin sole - its deep enough for them down there. This might be one of the best options. As well, many have replaced the red battery switch (off-1-both-2) with separate switches for each bank and maybe an emergency 'combiner' switch. Maine Sail has written some good posts about battery switching options, both here and on his web site. Here is a link to one of the longer threads for your reading enjoyment.
Several owners have put 6 volt golf cart batteries under the cabin sole - its deep enough for them down there. This might be one of the best options. As well, many have replaced the red battery switch (off-1-both-2) with separate switches for each bank and maybe an emergency 'combiner' switch. Maine Sail has written some good posts about battery switching options, both here and on his web site. Here is a link to one of the longer threads for your reading enjoyment.
Not to play devil's advocate, but when my surveyor just looked over our 37C he advised against putting batteries in the bilge. He said if it flooded it could cause the batteries to explode. I am still trying to find a good spot for ours.
There are a lot of urban legends about saltwater and batteries. Explosions of lead acid batteries are usually a result of hydrogen that is off-gassed during charging being ignited by a spark. This can happen no matter where the battery is located - venitilation and using suitable electrical equipment (marine grade battery switches and alternators, for example) is the answer. The amount of hydrogen released is small and, because it is lighter than air, dissipates quickly. However, any battery exposed to saltwater could also release small amounts of chlorine gas. This is the old "submariner story". Unlike a submariner, on a sailboat you can get to fresh air pretty quick, minimizing the risks. The real danger of saltwater mixing with the battery is that it will likely ruin an expensive battery. I will also add that, if you have saltwater above the floorboard in a Hunter 37 Cutter, you have a bigger problem than submerged batteries - you have well over 100 gallons of bilge water and a serious leak somewhere! (I am assuming anyone mounting batteries in the H37C bilge will arrange to have the battery tops just under the floorboards.)
Before I decided to place batteries in the bilge, I did the research and analyzed the risks; anyone else contemplating relocating their batteries should do the same.
On Midnight Sun I built a platform under the vberth. I have 4 group 31 AGM glass mat batteries there and one group 24 AGM battery in the original location. Battery1 on the switch in the galley selects the forward bank of four. Battery 2 selects the engine battery aft to start the enging. I have two more battery switches forward so I can select one battery at a time if I choose. It is simple very effective, and keeps batteries out of the bilge.
You could extend the cabinet behind the steps into the cabin a bit and stack and put them forward of the engine. I used the space above the shower sump on the 33C. See my approach at http://richgard.com/h33celectrical.htm
I have 2 house bank batteries located on a shelf under the aft cabin berth. Don't know if that's the "ideal" location, but that's where the PO put them and it made sense to me.
Under the aft cabin berth? On my boat that is all fuel tank, there is no open space.
Love my bilge installation, didn't have to build anything.
Love my bilge installation, didn't have to build anything.
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I think some of the earlier boats (incl. Fred V?) had the fuel tank under the cockpit sole. Are those 'golf cart' batteries Ed? What's keeping them secured in the bilge?
Yup, fuel tank was under cockpit directly behind the engine. A real bear to remove! I replaced it with a new tank in the same location.
Yes, two 6 volt Delco Marine batteries per Maine Sail. Just the normal straps secure them. My sole panels fit very snug and I have no plans for anything more than 60 degrees. 
Nice installation! Impressive cabling and the prerequisite battery fuse too. All "according to Hoyle".Yes, two 6 volt Delco Marine batteries per Maine Sail. Just the normal straps secure them. My sole panels fit very snug and I have no plans for anything more than 60 degrees.