Best Battery Location?

[Ironworker]

I was planning on using Group 31's in my B31. Two cranking batteries and two batteries for the house bank which would be located in the bilge just as you enter the cabin, forward of the engines. A friend gave me a pair of 8Ds which I have in the boat temporarily.

Another alternative is moving the batteries to the generator platform (I have one on the port side unused and I'm building another platform on the starboard side beside the engines. If I did this, I'd go with the Group 31 batteries. Two batteries on each side or possibly 3 on one side and one cranking battery on the other side to balance the weight depending on what I do in the cabin.

I know the advantages of getting the batteries out of the bilge but what am I missing with locating the batteries in the engine boxes. I know I will be shifting the CG aft and should get a more bow up ride which I'm already getting because I have a light boat.

Thoughts?

[Tony Meola]

Rick

Originally the 31 came with the batteries outboard of the engines. Most of the repowers members try to place the batteries centerline between the engines in the companionway area.

That keeps the weight low and in the center of the boat. Mine are still outboard of the engines, but I have sea water strainers located in the companionway area and we are a little overkill with the batteries, with two group 31's for each engine and one for the house for 5 batteries in all.

I have 3 batteries outboard of the port engine and two outboard of the starboard engine along with the holding tank.

If I was doing it again, I would put the strainer plates on the hull and eliminate the inboard strainers and try and put the batteries centerline between the engines. My only reason for that would be to allow me to install a larger holding tank. Otherwise the boat is well balanced.

[Ironworker]

Tony,

That is good information. It sounds as if my batteries are in the right place. I'm looking for a good place for a tool box and spare parts so the platforms outboard of the engines may be there right place for those. Thanks

[Rawleigh]

My '66 came with them between the engines. It keeps the CG centered and low, but runs the risk of flooding them in an emergency.

[Ironworker]

That's what I thought as well. Maybe a possibility for both!

[Tony Meola]

Rick

I know a guy with a Carolina Classic its a 28 footer. What he did and I have thought about this, he put a platform in the bilge area, under the deck up in the cabin. He then secured a tool box to it, so if he needs tools he just needs to lift up the hatch and open the tool box.

I never measured to see if it would work in our boats. Problem I see with it being outboard of the engines is if you need to get at them while the engine is hot, you are leaning across a hot engine.

[Ironworker]

I thought about that as well. But we are limited on space and that area is so inviting to put something there.

I have filled my companionway under deck areas in the bilge. One has a 3 KW pocket transducer and a livewell, washdown pumps. Another has batteries and the most forward area has a bilge pump.

[EarleyBird]

For what it’s worth...I have two Interstate 31P-MHD, CCA 950 batteries outboard of the starboard motor. My Phasor 3KW generator sits on an identical platform outboard of the port motor. Two parallel switches above the batteries. Only two batteries. Renew them every three regardless. Battery charger in the head behind and below sink in cabinet. Night fishing with spreader lights or cooking, Frying Pan, Microwave, Coffee pot generator is ran. Never a problem. EarleyBird

[trace elements]

For those with their batteries in the bilge between the engines, do you have any concern about the batteries being submerged/shorted in the event of bilge flooding?

[Snipe]

I am putting four group 31’s in the center bilge. I believe this is the best spot to put them for weight distribution. If you build a proper box water proof up to the lid it would take a lot of water in the bilge to flood the batteries.

[Rawleigh]

The original batteries were in a lidless fiberglass box similar to what is shown above to protect from flooding. If the water gets that high it is probably too late anyway.

[Yannis]

In my 28, there is ALWAYS water in that part of the bilge, whatever I do.
I wonder if it is also the case in the 31.
There is also the corresponding muck that builds on the hull as water is permanent.

Every so often, I open the middle hatch and drop a few drops of dish soap and agitate with the broom, so that the muck is detached from the surfaces and also pour in a couple of buckets of sea water, the bilge pump does the rest.

How does one plan to clean what’s under that battery box? Water movement alone cannot detach oil residue and growth without some agitation with a brush or broom, that obviously cannot reach under that box.

[Snipe]

Yannis there is water usually in that part of the bilge. I made the box removable if I ever have to take it out it’s just four bolts. Top of the box is 13inches out of the center of the bilge.I am thinking about building a set of trays to hold some oil diapers under the engine to keep the bilge as clean as possible.

[Rawleigh]

I use the pressure washer and dish soap to get under it whenever I haul and clean the bottom. You can do an OK job with a hose nozzle if you push it right up under the box. Generally I do not have much in the bilge. I have dripless stuffing boxes and the boat stays in a boathouse except for hurricanes. My bilge is usually dry.

To my knowledge the batteries were always in the bilge unless they were needed outboard to trim ship when a generator is outboard of the other engine.

[bob lico]

snipe you are spot on the only way!!!!!!! lets start by say when men were built of iron and ships were built of wood a boat designer wanted to reinvent the wheel in sailing ships after all sailing ships have been around for 5000 years prior to that famous day in 1851 when the boys from Boston MA. put a new concept of clipper ship into the wind. the flying cloud made a mockery out of the best sailing ships of the day almost twice the speed in actuality. made a record run from NY to SF that record stood for a hundred years. the sails were way to much and the ship would flip over so they said BUT a new theory was used by putting the bulk of the weight down the centerline of the keel to have the lowest center of gravity possible to offset the huge amount of sails. this is why we have fuel tank in center, batteries,fresh water tank and for some a live well in center. this is the best possible solution to the snap roll cause by ridiculous side fuel tanks, batteries mounted on the outside of engines and the most ignorant of all OH the water may go over the batteries (trust me brothers when the water has reach the top of the batteries 1" lower than cabin door your going down ) you should have open the crash valves long before this!!!!!. when the water is over the batteries the scuppers are under water " brilliant deduction to hearsay"the only place to place 4 type 31 batteries is the CENTERLINE on a shelf so the top of batteries are 1/2" under the lid.