I have a 1994 35.5 legend, The house bank batteries are located in the port side lazarette, I would like to move them to a better location. currently there are 4 batteries enclosed in Battery case holder(s) with covers.
House bank battery location
- Thread starter drkmcdaniel
- Start date
Battery-bank location suggestions
Look around. If you have to, make a mock-up of the batteries out of a cardboard box (or, as I have done 'professionally', sticks and hot glue) and start fitting it into the boat. I presume you will want to split these into two two-battery banks, so as to put half on each side of the boat. I would start by looking under the bunks and under the sole.
In my opinion the best place for house banks is under the main-cabin settee/berths, preferably aligned with the after end of the keel. This places the weight down low and centrally, fore-and-aft-wise, affecting trim less there than at any other place in the boat. Even if they end up being a little higher in relationship to the waterline than would be optimal, by putting half to one side and half to the other that weight actually sort of evens out, like at higher angles of heel.
On my H25 I cut open the tops of the bunks, making new access hatches there, and installed-- from the bottom-- a plastic battery box from West Marine in each one. These I screwed into the wooden frames I made in the holes. You can't get them out any more-- the frames are glued in and they sort of encompass the lifting ears of the plastic boxes. The boxes do not have drains. They do, however, have vent pipes, in PVC, leading from the upper after corners of the boxes directly aft, in straight lines (no sag), into the lazarette where they are fitted with 'snorkels' to allow the hydrogen gas to escape to where vents can waft them out. This is important for any installation of lead-acid batteries (and often overlooked). Some builders fit vents on the settee fronts, so we all get to breathe and smell the acid-laden hydrogen. Others, more heinous, do nothing and allow this gas to seep out the box lids and rot out the bottoms of your cushions and much else. #theboatbuilderisnotyourfriend :naughty:
Installing batteries in the bilge is ideal for performance and design considerations, but not necessarily for engineering ones. The boxes will have to be sealed from water running down the sole, always a possibility, but be immediately accessible for inspection and maintenance. They also have to be isolated from contact with bilgewater, for a variety of reasons. This is the number-one violation by boatbuilders installing batteries in the bilge. Some just stand them naked on the bottom of the boat!
Venting the gas from the bilge will be more complicated as well (you have less room to keep the pipe straight-- and don't use hose). But, if you can do it, this is best for weight distribution and where they will fit tends to be a centralized location for electrical distribution as well (shorter wiring).
Any time you split the physical bits of a single battery bank, remember that they still have to be wired as one. That means never disconnecting them for any reason. If you must split them on opposite sides of the boat, one good idea is to oversize the connecting wires. This limits loss of current when only one is tagged for the load or for the charging cables. I did this on Diana too. But otherwise it's really the only problem and not worth disregarding the rest of the benefits for.
I don't care for batteries in the lazarette, really ever. It's too far aft, so it affects the boat's trim in a place you probably already have too much weight now. And it's exposed to too much loose gear, engine heat, and potential for water crashing through the seat-locker hatches. Now try to get your head down on top of the batteries to inspect them back there (which is probably what you've already thought of). Any time you can relocate them (or design them to be elsewhere from the start) is an automatic improvement.
I installed a battery box back there for Diana's outboard-motor starter but it's in another plastic box, this one half out of the floor back there, with its own cover, as far forward and as inboard as possible. Unfortunately it's on the same side I sit, both in the cockpit and down below, so being small the boat can get a little out of trim. I countered by putting the larger of two water tanks under the settee on the opposite side; but I can't tell you it'll ever be full unless I am crossing an ocean.
Look around. If you have to, make a mock-up of the batteries out of a cardboard box (or, as I have done 'professionally', sticks and hot glue) and start fitting it into the boat. I presume you will want to split these into two two-battery banks, so as to put half on each side of the boat. I would start by looking under the bunks and under the sole.
In my opinion the best place for house banks is under the main-cabin settee/berths, preferably aligned with the after end of the keel. This places the weight down low and centrally, fore-and-aft-wise, affecting trim less there than at any other place in the boat. Even if they end up being a little higher in relationship to the waterline than would be optimal, by putting half to one side and half to the other that weight actually sort of evens out, like at higher angles of heel.
On my H25 I cut open the tops of the bunks, making new access hatches there, and installed-- from the bottom-- a plastic battery box from West Marine in each one. These I screwed into the wooden frames I made in the holes. You can't get them out any more-- the frames are glued in and they sort of encompass the lifting ears of the plastic boxes. The boxes do not have drains. They do, however, have vent pipes, in PVC, leading from the upper after corners of the boxes directly aft, in straight lines (no sag), into the lazarette where they are fitted with 'snorkels' to allow the hydrogen gas to escape to where vents can waft them out. This is important for any installation of lead-acid batteries (and often overlooked). Some builders fit vents on the settee fronts, so we all get to breathe and smell the acid-laden hydrogen. Others, more heinous, do nothing and allow this gas to seep out the box lids and rot out the bottoms of your cushions and much else. #theboatbuilderisnotyourfriend :naughty:
Installing batteries in the bilge is ideal for performance and design considerations, but not necessarily for engineering ones. The boxes will have to be sealed from water running down the sole, always a possibility, but be immediately accessible for inspection and maintenance. They also have to be isolated from contact with bilgewater, for a variety of reasons. This is the number-one violation by boatbuilders installing batteries in the bilge. Some just stand them naked on the bottom of the boat!
Venting the gas from the bilge will be more complicated as well (you have less room to keep the pipe straight-- and don't use hose). But, if you can do it, this is best for weight distribution and where they will fit tends to be a centralized location for electrical distribution as well (shorter wiring).Any time you split the physical bits of a single battery bank, remember that they still have to be wired as one. That means never disconnecting them for any reason. If you must split them on opposite sides of the boat, one good idea is to oversize the connecting wires. This limits loss of current when only one is tagged for the load or for the charging cables. I did this on Diana too. But otherwise it's really the only problem and not worth disregarding the rest of the benefits for.
I don't care for batteries in the lazarette, really ever. It's too far aft, so it affects the boat's trim in a place you probably already have too much weight now. And it's exposed to too much loose gear, engine heat, and potential for water crashing through the seat-locker hatches. Now try to get your head down on top of the batteries to inspect them back there (which is probably what you've already thought of). Any time you can relocate them (or design them to be elsewhere from the start) is an automatic improvement.
I installed a battery box back there for Diana's outboard-motor starter but it's in another plastic box, this one half out of the floor back there, with its own cover, as far forward and as inboard as possible. Unfortunately it's on the same side I sit, both in the cockpit and down below, so being small the boat can get a little out of trim. I countered by putting the larger of two water tanks under the settee on the opposite side; but I can't tell you it'll ever be full unless I am crossing an ocean.