When are battery boxes required?

[TimmS]

I'm installing an AGM battery in a locker under a deck hatch. am I supposed to use a plastic "battery box"? I do have one here, but is is bulky and ugly. The battery will never get wet unless the hatch is open in rain/spray, and it is a completely sealed battery. the only advantage I see with the box is that the terminals are covered. Thanks for your input.

[Lew Barrett]

And that, I think, is the big benefit; having the terminals unexposed. There are other ways to accomplish that; I'll see if I can dig out some photos of how we did it.

[redbopeep]

Some more knowledgable person will come along with a better answer...but here's what I know:

1. It's good practice to use a battery box and I think it's probably an ABYC or other standard requirement anyway.

2. AGM batteries are still lead acid and if the case is damaged there will be an acid leak.

3. There are some batteries out there where the case of the battery itself is double walled and a battery box is not required. We were looking at large 6V batteries for a house bank and I'm thinking it might have been Rolls Surrette...or a Crown battery...or possibly one of the Trojans...can't recall which.

4. You can make your own prettier battery boxes--glass over plywood is common--if you don't like the ones available at the marine stores.

Good luck in your project :)

[rbgarr]

The ABYC Standards that apply to battery installation, Section E-10.7, are a bit lengthy. Call ABYC for the full details.

The main points, paraphrased and abbreviated:

Provide for containing electrolyte leakage or spillage (up to complete leakout), and isolate it from any boat structure that can be attacked by the electrolyte, including fastenings that secure the battery.

The battery should not move more than one inch in any direction (even upside down) when 90 lbs. of pulling force (or twice the weight of the battery, whichever is less) is applied for one minute.

Each battery terminal shall be protected from contact with metallic objects.

It may not be mounted above or below a fuel tank, fuel line fitting or fuel filter. Each metallic fuel line or fuel system component within 12 inches of a terminal or above the horizontal plane of the terminal shall be protected with dielectric material.

A venting system or other means shall be provided to permit the discharge of hydrogen gas released by the battery. (This includes plastic battery boxes and sealed batteries. See ABYC Standard H-2, Ventilation)

Batteries shall be charged by means of an automatically controlled device that is capable of applying the current and voltage appropriate to the type of battery being charged.

[D Happ]

I don't think you can call ABYC on the phone and get info, can you? It seems you have to pay for it, but I don't know.
I follow the Coast Guard Boat Builders Handbook (http://www.uscgboating.org/safety/boatbuilder/index.htm). It’s free and I think it parallels ABYC pretty close, but probably not exactly.

[rbgarr]

I don't think you can call ABYC on the phone and get info, can you? It seems you have to pay for it, but I don't know.

Probably so, but I was hoping they'd encourage Tim to join. There's so much good information in those standards. As a pro builder he would probably get a rate on membership dues.

[Lew Barrett]

We made our "box" out of plexi, but it isn't exactly what ABYC calls for. On the other hand, the batteries are tied down, but good and there is a catchment area for liquid. It's easier to show the picture than to explain what we did, as there is some fabrication that was rewquired. In my case, in order to get the capacity I needed in the space I had, I was forced to a custom solution. It might be just as easy to go with a commercial box for a single battery if following the rules is important. I will post some pictures for you, and that will be easier than trying to explain it. In practice, access to the batteries and cabling is important, so keep that in mind.

[TimmS]

Thanks to all of you. I just finished the installation, and did use the plastic box that I bought. I think it is best in this case. I would definitely enjoy seeing photos of any special installations any of you have done....post away :) I looked into joining ABYC about a year ago and turned it down due to cost. if you guys think it is worthwile, I will check into it again. Goodnight

[Peter Eikenberry]

Just to make it clear. Battery boxes are not "required" by ABYC or the USCG. rbgarr laid it out pretty well. The point is that the battery can't move, any leakage will be contained, and the positive terminal is protected for inadvertant contact. This can be accomplished in many ways, a battery box being one of the ways.

ABYC is very worthwhile. I have been an active memeber since 1984.

[boylesboats]

I think battery boxes is cleaner in appearance than ugly, corroded, dirty, acid covered batteries...

Why not a good battery box/case?
It'll keep battery mess inside, keep your boat cleaner, and less accidental contact to exposed batteries

[mmd]

When are battery boxes required?

...when you put the battery in the boat.

(Sorry, I couldn't resist! <wink, grin>

Seriously, though,; I wouldn't put a battery in a boat without a battery box. Protection of the battery from knocks, easy to strap down, protection of the terminals from shorting, protection of the hull from spilled acid, etc. Too many good reasons to not spend fifteen or twenty bucks.

[Torna]

I made one for Torna's batteries a few years back: simple shaped plywood box lined with fiberglass & (West) epoxy.
But upon inspection after 3 years of mild service (though certainly with a bit of battery ooze) it looks like the acid leakage has eaten away the epoxy - leaving only the glass and wood.
I haven't done a proper post-mortem or tested it again. Maybe someone else can confirm or deny this.

-leif

[willmarsh3]

When I had my little incident with overcharged gel cells it was a very good thing I had battery boxes. There was lots of acid spillage.

[TimmS]

thanks for the thoughts, when I posted this I was thinking in terms of rain/spray/sun damage, not spillage. I'm glad I used the box and will continue to do so. And MMD- it definitely was not a cost issue :D it's probably the cheapest piece in the boat after the key chain ;)

[rbgarr]

Tim,

FY(future)I

ABYC compliance guidelines on some topics are available to non-members: http://store.abycinc.org/merchant.mvc?Screen=CTGY&Store_Code=ABYC&Category_Code=COMPLIANCE_GUIDELINES

The 'Electrical' would deal with batteries, for example.

[starbacca]

The primary use of a battery box is to keep the battery in place and also to contain spills. Although you don' have those problems with an AGM it is still a good idea ( think insurance) to have the battery in a box. You can build a very nice box out of plywood and glass cloth. If you have ever had a battery explode ( I have) you will thank yourself for putting the battery in a sturdy box. My plastic battery box disintegrated when the battery blew up.

[Gary E]

The primary use of a battery box is to keep the battery in place and also to contain spills. Although you don' have those problems with an AGM it is still a good idea ( think insurance) to have the battery in a box. You can build a very nice box out of plywood and glass cloth. If you have ever had a battery explode ( I have) you will thank yourself for putting the battery in a sturdy box. My plastic battery box disintegrated when the battery blew up.

I have been around batteries for over 50 years and your the first guy I know of or ever heard of that had a battery explode... They usually just die.. What caused the explosion?

[Captain Intrepid]

I have been around batteries for over 50 years and your the first guy I know of or ever heard of that had a battery explode... They usually just die.. What caused the explosion?

Hydrogen gas buildup during charging I would presume.

[rbgarr]

It can also happen if they freeze and are then cranked really long. It's more of a bang/crack than explosion. Nasty nonetheless.

[willmarsh3]

We had a battery explode on our race committee boat. We were using a one stage charger. Hydrogen gas built up and eventually something set it off. Fortunately it was in a big battery box which didn't get much damage but part of the top of the battery got blown off.

http://en.wikipedia.org/wiki/Battery_(electricity)#Explosion

[Gary E]

Batteries being charged do give off hydrogen, but that is disapated into the surounding air, and even if it's concentrated in an explosinve ration, WHAT CAUSED THE EXPLOSION?

A charged battery will never freeze,
A dead or cold undercharged battery will just die as it fails to start an engine.

Batteries do not explode on their own.

[willmarsh3]

Batteries being charged do give off hydrogen, but that is disapated into the surounding air, and even if it's concentrated in an explosinve ration, WHAT CAUSED THE EXPLOSION?

The explosion occurred inside the battery. The top of one cell was completely blown off and the two adjacent cells were torn open. I suppose there was an arc inside between exposed positive and negative plates that set off the built up gas. Perhaps there was a voltage surge somewhere that caused the arc.

[Gary E]

The explosion occurred inside the battery. The top of one cell was completely blown off and the two adjacent cells were torn open. I suppose there was an arc inside between exposed positive and negative plates that set off the built up gas. Perhaps there was a voltage surge somewhere that caused the arc.

The only way an arc can happen is to have the top of the plates exposed durring charging..
You should know better than to let that happen.