Forum Discussion

netdefilr's avatar
netdefilr
Explorer
Jun 24, 2013

Replacing the battery due to overcharging.

I had over the weekend 2 issues. But this one is regarding the battery. I left the camper plugged in all week. I didn't know that I could overcharge a battery. The battery sat next to the propane tanks and while camping I assumed it was propane because of the rotten egg smell.
It turns out it was the battery.

I have an electrical panel and I found a switch that turns off the converter to power the battery. I replaced the battery the other day and don't want to run into this problem again. Could it have been that my battery was dead? Maybe I didn't add water to it? Or am I supposed to turn this converter switch on the electrical panel off?

Thanks guys,
Tim
  • I don’t know of any converter used in modern times functioning correctly that would cook a battery in a week…
    My first suspicion is the water level wasn’t maintained, but it could be the battery just went bad to…
  • netdefilr wrote:
    opnspaces:
    Yes I do. Should I check the battery without the connections made? You're talking about the new or the old battery now? I did buy a new one over the weekend to replace it.

    I'll try to post the converter make/model later when I'm in front of it.

    Thanks.


    First thing is I would replace the battery regardless of any tests. So my suggestion is assuming you're going to replace the battery.

    Pay attention to wire colors as you swap the batteries. Most trailers use white wires for ground. So swap the batteries and put the old battery on the ground.

    1) Old Battery: If you can open the caps, is there still electrolyte covering the plates in each cell. Fill any low cells until close to the split rings when looking into the cell. You can use any water at this point as you're getting rid of the battery anyway. Were the plates in any cells exposed?

    2) Old Battery: Put the caps back on and do a voltage test. There are six cells in a 12 volt battery. That's why there are six caps or holes to fill with water. Each cell produces approximately 2 volts. So if your voltage reading is 10 volts you have a dead cell. What was your voltage reading?

    3) New Battery: Hook up the new battery to the trailer and take a voltage test. What was your voltage reading?

    4) New Battery: Plug the trailer into shore power and take another voltage test. What was your voltage reading?

    5) New Battery: If you can, let the trailer sit plugged into shore power for the day/night and then check voltage. What was your voltage after sitting on shore power overnight?
  • How old is the old battery? If it is four, or more, years old, it probably needed to be replaced, any way.

    Trailer battery (electrolyte) does need to be serviced from time to time. If cells get to low on electrolyte, they can short out.
  • If you have the old battery, measure the voltage with it disconnected and out of the trailer. Normal battery voltage is 12.6 volts for a fully charged battery. It may be as high as 13-something with a surface charge. A reading of 11.5 volts means it probably has a shorted cell.
  • You are not overcharging the battery due to a bad converter. What happens is that one of the cells in the battery is shorted. This makes the converter think the battery is low and it works hard to get the battery up to full charge. Pull the battery and take it somewhere and have it load tested. I am pretty sure you will find one of the cells shorted.
  • RoyB's avatar
    RoyB
    Explorer II
    I doubt he has a smart-mode converter/charger unless he has added it himself... My 2008 model didnt come with one...

    The converter/charger that put out a constant 13.6VDC will start boiling out the battery fluids and when the fluid gets below the core then the batteries go into self destruct mode. This can happen in as little time as 4-5 days...

    Changing out your old converter/charger for a smart mode converter/charger is easy to do if that turns out to be the problem...

    Just my thoughts
    Roy Ken
  • opnspaces:
    Yes I do. Should I check the battery without the connections made? You're talking about the new or the old battery now? I did buy a new one over the weekend to replace it.

    I'll try to post the converter make/model later when I'm in front of it.

    Thanks.
  • Welcome to the forum netdefilr,
    If your profile is correct you have a 2006 Salem 20FB trailer. I would bet that it already has a 3 stage charger. It's possible you had a shorted battery and the charger overcharged it trying to bring it up to full.

    Do you have a multimeter? you could plug in the trailer and then check voltage at the battery?
  • What's the make / model of the converter? Most modern converters have "smart" 3-stage charging built in and don't need to be disconnected or shut off.

    But - if the battery had a shorted cell the converter would try to charge it as a depleted battery. This would result in boiling the battery, outgassing, and the rotten egg smell. Getting the battery tested at an auto parts store would give you the answer.
  • If you have a good converter that has a float stage your battery shouldn't overcharge. Check the specs for your converter and determine if it does have a float, or what could be described as a lower voltage maintenance stage, about 13.1 volts. Then check the voltage while your converter is charging with a multimeter and make sure it is working correctly. Hard to say what might have been the problem with the other battery, check your batteries on a regular basis to make sure they have adequate electrolyte and they are holding a charge.

    By the way, welcome to the forums!

    Miles