Battery Bank Where?

[GILow]

Originally Posted by Delancey

Just curious to know where people have found the best location for a house battery bank to be? Maybe 400 amp hrs worth on a 40 foot monohull. What works and what doesn't and why.

Cheers

Similar sized boat and bank in our case. I brought ours from the stern cabin to midships, starboard side, under/behind the main settee. A few reasons:

1. It brought the power source much, much closer to the devices that required the power. I still have rolls and rolls of spare high current cable that I was able to remove from the boat altogether. (this includes HALVING the distance the cables had to run for the windlass, which was a big bonus.) There is less than 12 inches of battery cable from the batteries to the main power panel.

2. Bringing the bank forward improved the fore and aft trim and removed weight that might contribute to hobby-horsing.

3. Putting it on the starboard side balanced the boat better, the boat was heavy on the port side from the galley. This was actually quite a problem when slipping the boat.

4. I was able to mount the batteries lower at that point in the boat than where they were at the stern, a good two or three feet lower, so lower c. of g. It all helps on a mono.

5. They are in a much more easily accessed place than tucked away up the stern. They are right there in the main cabin where you can get to them without special tools or removing panels or stored equipment, and where it is sheltered, and dry, and probably the most temperature stable part of the boat.

Downsides:

1. Ventilation is going to be an issue when I swap out the AGMs for flooded. The old setup vented to the engine bay, the new location will need a vent pipe run to the deckhouse, with a swan neck fitting or similar. Fire risk aside, I don't like the idea of battery fumes in the main living space.

2. They are lower in the boat so more vulnerable to water ingress if we spring a leak, but they are still much higher than the keel, which I considered but ruled out because I really did not like the idea of them getting flooded in even the most trivial of leaks.

Good luck finding a home for your battery bank,

Matt


P.S. Our engine battery bank is totally separate, it has to be as it is 24 volt. I left it up the back in the original location (close to the engine starter and alternator) as the two batteries are relatively small and light compared to the house bank.

[UNCIVILIZED]

For the OP, I'd go with the under the cockpit location. As you don't really need to access the batteries all that often. Usually doing so is part of periodic maintenance, when you check their fluid levels.

Said location would also have the benefits of putting them near the engine for charging, & situate them reasonably high in relation to the ship's waterline.

As to hydrogen, it seems that it's pretty much a non issue. As discussed here. http://www.cruisersforum.com/forums/...ml#post2234911

[Terra Nova]

Generally you want the weight of the batteries low and centered, with short cable runs to panel, starter and windlass. Easy access for maintenance and replacement. And all batteries in a bank close to each other and of the same type, manufacture and age.

[siamese]

MaineSail has some excellent information on battery location at:
marinehowto.com

A couple of major points are:

1. Heat kills batteries. Locating them in the engine compartment is a no no. I was looking at pictures of the battery box in a current production 28 foot sailboat and it was crammed into the engine compartment. Not good.

2. Ideally, they should be located where the long measurement of the battery runs transversely, not longitudinally with the keel. If they're located along the length of the boat, when the boat heels, the battery plates can be lifted clear of the electrolyte. While not catastrophic to the battery, it does shorten their life. My Catalina 28 has the batteries oriented in the wrong direction. Take a look at the pictures that MaineSail has on his site to see the downside of wrong orientation.

3. At least my Catalina 28 has the batteries close to the main panel, and in a spot where I can get to them easily. If you have to crawl or slither, you're more likely to put off checking the electrolyte levels.

[Colin A]

Originally Posted by UNCIVILIZED

For the OP, I'd go with the under the cockpit location. As you don't really need to access the batteries all that often. Usually doing so is part of periodic maintenance, when you check their fluid levels.

Said location would also have the benefits of putting them near the engine for charging, & situate them reasonably high in relation to the ship's waterline.

As to hydrogen, it seems that it's pretty much a non issue. As discussed here. http://www.cruisersforum.com/forums/...ml#post2234911

This is one of those places (like CO and smoke detectors) where the RV industry seems more stringent then marine. A couple years ago I was talking with some one who worked for the RVIA (kind of like if the NMMA and ABYC was one organization) He stated that any battery in a living space had to be vented to the exterior due to out gassing. This is standard required for RV certification under RVIA. He also mentioned at the time that a little arguing in the RV industry over AGM and Gel cells was happening. Most manufacturers vented these to the outside too, but a few felt it was unnecessary.
He said he knew there had been some testing done by one large RV builder who found some outgassng on AGM when trying to charge at a high rate so they still vented them outside.

ABYC it should be noted also calls for a battery to be vented to the outside in the E-10 standard.

Now that said I have been on tons of boats with batteries vented to the interior and there are very few reported problems I can find, most of the boats I have had them under the dinette settee with little issue. Current boat they are in one of the cockpit lockers (which is vented to the cockpit)