House Battery Exploded

[AFChap]

A day or two ago I noticed fresh liquid marks on the pavement under the battery compartment ...I didn't think much of it because it is right beside the basement a/c that is always dripping water. It looked like it could have been from the front of the ac compartment.

This morning I noted the marks still there, and a small one also near the front of the battery compartment. I opened the compartment door and saw traces of leakage under the house battery bank tray. I checked the batteries and found the cap off the positive end of the innermost of the three batteries. None of the batteries felt more than slightly warm, and all appeared to be normal on the monitoring panels. Fluid level was ok everywhere else, but there I could see the plates in those cells. I added a considerable amount of distilled water and then noted water running on the ground. I could see no damage to the battery, but then I removed the batteries I found it split from top to bottom in three places on that rear corner, and the top was separated from the sides on that side and about half of the back.

There was no other indication that anything was wrong ...all 12v items and power monitors were normal. I have a triple-stage charger that goes to float mode so it will not overcharge the batteries, and appears to be operating properly. There is a heat monitor that will shut it down if the batteries over-heat. The terminals were a little dirty, but not at all bad. Outside temps have been over 100 for most of the past two months. These batteries are almost exactly 4 years old. I check the water levels every other month and have had to add water only once in the four years they have been installed ...that was in July 2010.

I see nothing to suggest there is any problem with the charging system. Was this likely the result of an internal battery short? I've not experienced this kind of battery failure before.

...and I do have three new batteries installed and working...

[akadeadeye]

Paul,

I am no expert. I check my batteries while the coach is in storage the first of every month and I always have added water to each cell of the 4 6v deep cycle batteries. I am hooked up to 20 amp service while in storage and also have a three stage on-board converter/charger and it reads either float or full charge every time I check the monitor. I am surprised by your statement that you seldom add water.

Don

[tomwalt]

I had this hapen to me (see my post "Battery be gone"). Prior to the battery blowing up I noticed that the ba battery required much more water than the other - all indications remained normal on the monitor panel even after the exodus of the battery. Like you, my onlyindication was water (acid) on the ground. I did not figure out that the battery had an internal short until it boiled off the water and blew up. I used a couple cans of battery acid cleaner available at Auto Zone to spray everything down in my engine compartment to ensure acid fumes didn't get embedded and start corrosion. You might want to do the same if it applies to you.

[Jim-in-Hope]

How tight were the battery hold down clamps? If the clamps are too tight when the batteries get hot the will expand and can rupture the case. The clamps should only be tight enough to keep the batteries rom moving.

[wa8yxm]

It may have been a cell shorted on the battery (or 2) when that happened the remaining batteries and the converter all started dumping amps into the now 10 or 8 or even six volt battery trying to bring it up to full 12 volt charge levels, of course they could not do it, nor could the remaining cell(s) in the battery take that kind of overcharge.

Recommendation.. A good soda wash of the entire battery area to remove any traces of acid.

[RV Wizard]

A collapsed plate can cause internal short that may also cause rupture of the case. Plates can collapse for a number of reasons. Here are a few links for more info:

U.S.Battery/Leader in Deep Cycle Batteries
Frequently Asked Questions (FAQ) - DC Battery Specialists
Deep Cycle Battery FAQ
http://www.rvsolarelectric.com/sources.htm
Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and

[AFChap]

Quote:

How tight were the battery hold down clamps?

No clamps. The three batteries sit in a tray and a fabric strap running over all three standing side-to-side.

[Jackm]

A few years ago, our chassis battery exploded when I inadvertently started the generator while plugged in. I cleaned up with baking soda and water until all foaming stopped and then hosed it off again with fresh water. About two months later, the motorized steps fell off. When I investigated the cause, I noticed that all four bolts that held the step motor in place had failed.

When I called Kwikee, they told me that they had never seen a catastrophic failure like that. That's when I discovered that battery acid had seeped into the space (under the battery compartment) where the step motor was attached and dissolved the bolts. The point to this story: make sure that you get everything clean. You may have to actually take some things apart. Baking soda works but it may not get into the hidden spaces that you can't see. At any rate, I'm glad no one got hurt.

Jack

[Tyler6357]

Quote:

Originally Posted by Jim-in-Hope How tight were the battery hold down clamps? If the clamps are too tight when the batteries get hot the will expand and can rupture the case. The clamps should only be tight enough to keep the batteries rom moving.

Wow, good tip!! I'm going to check mine tomorrow.

[ralper]

Sulphuric acid (battery acid) will cause steel to crystalize. I found this out many years ago when a drain snake fell into pieces while using it after I had used it a week or so previously in a drain someone had put sulphuric acid down. The company that made the snake requested some of it be returned to them for analysis and they told me why it failed.

If the battery was not charged it could have frozen and broken if you were where the temperature goes that low.