Forum Discussion

fizikpal's avatar
fizikpal
Explorer
Oct 26, 2017

warm/hot house batteries

Came home last night and heard the propane detector going off and there was a funny rotten egg smell. Hopped onto the internet to determine the potential cause (there are several) with one being the house batteries cooking. Low and behold went to go check them and sure enough they were warm to the touch and the area had a very strong odor.

Why they get hot. Could be that one, or both batteries, failed. Could be the converter is shot. OR..... Please fill in here.

The batteries were from Walmart and I had my receipt. BTW some good advice I got from here. Seal your receipt in the area you keep the batteries. If you ever have a problem you have the receipt right there.

Anyway, pulled out the batteries, went to Walmart and asked for an exchange. The batteries were 2 years and 4 months old. People there were extremely helpful and exchanged the batteries for free. I am hoping that this is the issue. I do not relish the idea of exchanging out the converter. Which would be next.

10 Replies

  • Tom,

    Glad to see you are getting your arms around it.

    You are now at the point were we can supply very meaningful assistance. Please keep us in the loop and I will bet that we can save you some grief. Nothing like a native guide.

    (BTDT - didn't buy the picture, and the T-shirt wore out long ago.)

    Matt
  • SO far all is good.

    Converter back on and batteries are read 13.3. I will check again in an hour.
  • Ok.. surprised to find the converter was just plugged in. Will follow through Matt's suggestions.

    tom
  • Matt,

    Not sure how I power up the converter. It of course is not in an easily accessible region (I have to remove a shelf that is screwed in but the last time I checked it I did not see a bypass or on/off switch.

    Can you please explain.

    And yes they were 2 12Vs in parallel. I replaced the batteries at no cost but will use the multimeter to test as prescribed.

    thanks all.

    tom
  • If one or both batteries became ill, the charger would not stop charging because a full charge could never be achieved. Then boil-overs and warm batteries occur.

    Like yourself, I had a pair of 12V Walmart batteries. I got two good years from them, one fair year, and one poor year. Prior to the Walmart's, I had the batteries that came with the rig when new. The story with both pairs was identical.

    After repeat experiences with pairs of 12V batteries, for the last replacements I got a pair of 6V AGM batteries from Sam's Club at nearly twice the price. Year #3 has been just as good as year #1. You'll have to ask me one & two years from now how they are doing.

    One thing I noticed about the 6V AGMs, they hold more energy so I am not charging as frequently. There is an improved "Quality Of Life" that comes with the change-up.

    One additional item I added which helps, was installing a volt meter in plain sight as shown. When electrical operations are at rest and the meter reads 12.1V, it's time to charge the batteries.
  • fizikpal wrote:
    Came home last night and heard the propane detector going off and there was a funny rotten egg smell. Hopped onto the internet to determine the potential cause (there are several) with one being the house batteries cooking. Low and behold went to go check them and sure enough they were warm to the touch and the area had a very strong odor.

    Why they get hot. Could be that one, or both batteries, failed. Could be the converter is shot. OR..... Please fill in here . . .



    When the batteries are overcharged, shorted, or discharge large amounts of amps for extended periods of time, they will off gas hydrogen, which, if close enough, will trip your propane detector. That's normal. As Matt (and others) mentions above, you need to find out why. It's normal for the batteries to get warm when charging and/or overcharging. If you are hooked up to shore power, it's common for the charging section in your load center (converter) to overcharge. In addition to a multi meter, a hydrometer could be helpful in determining if you have a bad cell or are overcharging.

    Chum lee
  • Tom,

    You wrote "one or both" batteries.

    If they are 12Vs in parallel, go buy a lottery ticket while your luck is holding. What you just had was the precedence to a battery explosion.

    If they are 6Vs in series, then either a single cell in one has shorted or the converter is over charging them.

    Either case, the diagnosis would be easier if you had any kind of a meter at all. Even the cheapie from Hazard Fright will do.

    When you come up for air and have your new meter in your hand, Disconnect the power to the converter. Let things sit a while. Measure the batteries - This should be something a lot like 12.6. If it is a lot higher, turn on an light for a few minutes - like 5 - Now are you down to 12.6?

    Turn the light off and power up the converter. Measure again.
    If the measurement does not increase by at least 0.3, the converter is dead, but I doubt that.
    If the measurement is ~13.3, the converter can probably be left alone.
    If the measurement is over 14.4, let it be for about an hour and try again. By then, it should have dropped to the mid 13s.
    If it above 14 for more than a could of hours, unplug the converter as it will trash your new batteries too.

    This is all a simplification of the check I would do before the depression put us out of business. If you find something that does not fit the cases above, come back here with what you do find. Getting a manufacturer and model number for the converter will also get you more accurate responses.

    Good Luck

    Matt
  • j-d's avatar
    j-d
    Explorer II
    Agree Times Ten on the MultiMeter. It sounds like overcharging. The Make/Model of your on-board Converter/Charger would be very useful in helping our electrical gurus to help you.
    Which Walmart batteries are you using? As I remember, the Starting batteries are three-year warranty and the Deep Cycles (like should be used as House Batteries) are one-year. I'd like to be wrong about that...
  • Do yourself a favor and buy a multimeter and learn how to use it. Randomly replacing parts can be a very expensive way of repairing your RV.