House Battery Blown Up

[Talley]

I keep my motorhome plugged in to 30A power out at a ranch and upon returning after a few weeks I noticed the house battery litteraly exploded. I do have a "disconnect" switch for both the house and main battery but did not disconnect either. Any ideas what happened? Should I use the disconnect switch when I leave the MH? Note, I have not checked the voltage while plugged in so not sure if my charger/converter is working properly.

MH is a basic 97 Fleetwood Flair if that makes a difference.

Not sure if it is a 3 stage charger or something more basic.

[andyshane]

We've had two explosions in the last three years, one with an obvious source of ignition near the battery.

In the second case, last Sunday, I simply sat down in my wife's 2010 Honda and turned the key. It was just like a car bomb, only non-lethal: the battery casing split along its top edge and an acid mist hung over the front of the car like smoke. No damage to the paint, thanks to immediate rinsing by yours truly. I immediately installed a replacement, was relieved to find everything was fine.

HERE is a discussion of explosion causes and effects. I'd rank motorhomes as a steeper risk than automobiles for such events during periods of inactivity due to way we use them. Before we get too technical, I'd like add that we all know what safety measures to employ; it's just a matter of disciplining ourselves to consistently apply them.

[wolfe10]

How often did you check battery water level? Most likely cause with they ran dry and the converter kept trying to charge them with one or more dead cells.

Start with a new battery, cleaning the battery compartment well with baking soda and cleaning and repainting what needs to be redone.

Post what converter, charger or inverter charger you have.

How often between visits to the coach-- that way we can come up with a safe protocol for keeping them up. Do you run any thing else on the coach on 120 VAC when you are not there?

Brett

[Talley]

Thanks all. Unfortunately, I just bought the RV a month ago and did not check the water level...shame on me. I will likely get two golf cart batteries and replace in a few weeks when I return. I will then also check model info on the charger.

I do leave it plugged in as I run the refrigerator. Nothing else should be on or running. Is this a bad practice?

[wolfe10]

I do leave it plugged in as I run the refrigerator. Nothing else should be on or running. Is this a bad practice?

Without knowing what converter, charger or inverter/charger you have, we can't answer that question. If you have a smart converter, charger or inverter/charger, you can safely leave it turned on 24/7 (IF it is properly programmed-- many allow you to program them).

Basically, you want the float voltage between 13.2 and 13.5 VDC.

[vagabond1]

I had the same problem with my Fleetwood Flair also and found out the batteries had gone dry. Cleaned and replaced them and so far all is good.

[mario.lamarca]

I am a total novice on the subject of batteries and suspect I may be having trouble with my 4x6v house batteries because: a) there seems to be a lot of acid corrosion around the batteries after only a few months since repainting the battery compartment and they are losing charge after sitting idle for prolonged periods of time (2-3 months).

These are new batteries, 1 yr old, so I should not be having trouble.

My questions: how much water is too much or not enough?

Is there an easy visual? I cannot see levels unless I open the top and look in each.

Also, should my solar panel not be trickle charging them on a regular basis, so they should never run low?

Any advice would be appreciated. I had to replace batteries last year because they went dry, dead and cracked.

[wolfe10]

Mario,

Several causes of excessive water use/acid from batteries:

1. A bad cell in a battery. This causes the charger to try to bring the charge in 5 cells to the same voltage as the normal 6 cells. That WAY overcharges the remaining cells. So, start by fully charging all batteries and then use a BATTERY HYDROMETER (under $10 from any auto parts house) to make sure you don't have a bad cell/bad battery. The very best charging equipment, when asked to charge a battery bank with one bad cell will do a very poor job.

2. Converter, charger or inverter/charger or solar panel(s) overcharging the batteries because it is not a "smart" charger, or is a smart charger that has not been properly programmed. Verify charging voltage AFTER charging source has been operating for at least 24 hours (i.e. should be in FLOAT mode). 13.0-13.5 is fine for wet cell batteries. More than 13.5 will over charge them, causing water consumption and expulsion of acid.

If solar is your primary method of maintaining battery voltage make sure your CONTROLLER is set to the proper voltage.

Brett

[tbutler]

I am a total novice on the subject of batteries and suspect I may be having trouble with my 4x6v house batteries

My questions: how much water is too much or not enough?

Is there an easy visual? I cannot see levels unless I open the top and look in each.

In answer to these two questions, there is no easy visual way to check a battery without removing the caps on the individual cells. When you remove the cap and look down into the cell you should see water over the plates of the battery. If water is not covering the plates your water is way too low. Look at the collar that extends down into the battery from the filler cap. Near the bottom of that collar there will be two slots positioned 180 degrees from each other. It looks like this ( ). The water level should be up to the bottom of the collar so that you can see it touching the collar but not filling the slots. When properly filled the water looks like it is curved up against the collar but flat where the slots are. The slots allow the gases produced by the battery to escape without forcing the liquid out of the battery in the process. If you fill the battery too full escaping gases will cause the battery to bubble over and the excess liquid will cause extreme corrosion. Corrosion is not evidence of the battery bubbling over, the escaping gases themselves will do that to any unprotected metal surface.

Each cell in a battery (a 6 volt battery has 3 cells and 3 caps) is filled independent of the other cells. The water/acid solution from one cell does not flow to the other cells. As a result you must check each cell and fill them independently.

You must use distilled water for filling your battery. Water that contains minerals will significantly shorten the life of a battery. Distilled water (do not confuse with drinking water) is available at all grocery stores. Likely your spouse is using it in the iron so you may find it under the kitchen sink or in the laundry room. Water from a faucet or garden hose is not suitable for use in batteries.

I use a long necked funnel available at auto stores to get the water into each cell without spilling large amounts of water in the process. It also allows me to see into each cell as I fill it. That way I can fill the battery just to the bottom of the collar and not overfill the cell. There are more expensive systems that can be used to fill batteries if you want to simplify the process. Google automatic battery filler to see some examples.

How often should you check your batteries? No less than once a month is advised. During periods of heavy use it is wise to check them more frequently. After you have done this for a while you will learn what is normal water use in your batteries. Then when the normal amount changes you will know to start looking for a cause and anticipating possible trouble.

[mario.lamarca]

Thank you for this very helpful advice! I have a lot to learn.

[schnauzerhome]

I had all 4 of my house batteries split and crack open last winter while the coach was plugged in. A new one for me. These batteries had been installed less than 2 years ago and were Interstates. I called them and they just gave me a lot of crap. The most likely reason was low fluid level causing freezing.

[desertdeals69]

I use a service station type battery type filler for the water. It has a spring loaded spout which when inserted into the battery filler neck fills and then shuts of when at the correct level. You don't have to look into the battery. They are avaiable at auto part stores for about $10 to $15. I built a carrier in the battery compartment for it.

[chucknewman]

Keep in mind a couple things with wet cell batteries:

1. The water level in the cells will be somewhat higher when fully charged vs when the cells are in a discharged state. Measure water level only when fully charged.

2. As wet cell batteries charge they produce hydrogen gas that is vented to atmosphere via the caps. Regardless of the electrolyte level. The heavier the charge, the more gas produced. As you should know hydrogen gas is very explosive when exposed to an ignition source.

Cracked and bulging batteries are caused by low electrolyte, over charging, aging, poor quality, etal. Batteries that "blow up" are due to excess hydrogen gas built up in the battery vicinity due to poor, or lack of, proper ventilation. There may be excess gas in the compartment due to overcharging conditions which is also slowly destroying your batteries. But I have seen batteries literally blow the top off due to excess hydrogen gas from insufficient air flow in the battery area, under normal charging conditions. A tech switched off a circuit breaker. This caused a small arc in the CB, which was the ignition source. The top of the battery hit him in the side of his head. I resolved the problem with the addition of continuous fans in the battery area.

I've had RV's, and have seen others with totally inadequate ventilation around the house batteries. I'm not saying everyone should run out and buy fans to install on the INTAKE side of the battery ventilation, but a couple little 3 inch vents for 2 or 4 batteries won't cut it either. You need to check your own coach. Don't assume the coach designers did everything right. Most of us have seen too many failures in that philosophy. Keep in mind the OP said his house battery "litteraly exploded" [sic] while sitting parked. Most likely due to a combination of over charging, excess gas venting, minimal ventilation, and an arc from any one of numerous sources inside or outside the coach.

And when working around batteries, always wear safety glasses or a full face shield. I use both.

Also keep in mind the "sealed" or "non-vented" or so called "dry cell" or "gell cell" type of battery is designed to vent gas, and will vent gas, when excess pressure occurs due to some mentioned conditions.

[mario.lamarca]

OK, I've gone from hopeful to nervous. Message taken, practice caution. Another naive question: if I engage my battery disconnect, for storage periods, does the solar panel continue to charge the batteries? (sigh, I have a long way to go!)

[wolfe10]

OK, I've gone from hopeful to nervous. Message taken, practice caution. Another naive question: if I engage my battery disconnect, for storage periods, does the solar panel continue to charge the batteries? (sigh, I have a long way to go!)

Mario,

Depends completely on where/how the solar panel and its controller are tied into your 12 VDC system. If you don't see wires from the solar panel/controller connected directly to the battery or between the battery and the disconnect switch, the answer is that it can't charge them with the switch in the disconnect position.

Easy to tell with a digital voltmeter (start under $20 at Sears, Radio Shack, etc). On a sunny day, with shore power and generator OFF, check voltage at the battery with the switch ON and OFF. That will tell you very quickly if the batteries are being charged. Charge voltage (float level) should be in the 13.2-13.5 range. Up to 14.5 VDC if the controller is in bulk charge mode.

Brett

[mario.lamarca]

Good idea, Brett, thanks!