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Chad_Jen's avatar
Chad_Jen
Explorer
Jun 19, 2017

Battery not charging

I was hoping to get some ideas to troubleshoot before I had to take our camper to the shop to get this problem figured out. Our battery seems to be dead, even though the camper has been plugged in and the battery connected for a week or so. We are leaving next week to camp and I wanted to try and have it figured out before then. I could put it on my charger but that wouldn't do me any good if it was just getting drained by use when the truck isn't running and the camper isn't plugged into power.

7 Replies

  • Sitting below 12 is hard on the battery and you may have already lost capacity to sulfation. Fully charging a low battery with a converter producing 13.6 volts will take three to seven days.

    I would disconnect the battery and use that portable as it will usually charge at a higher voltage. Use the recondition or equalization mode if available.

    How long will it last with two lights?
    We don't now the condition or size of the battery or how many. Neither do we know if the light is incandescent drawing 6 amps or LED drawing 1 amp. And there are other items idling at .3 to 1.5+ amps. Best to just give it a go in the driveway.

    The 12 Volt Side of Life
  • Thanks everyone. It seems that my converter is okay and the batter can fully charge. It was below 12 when I started it the other night, plugged the trailer in and charged the battery (to 13+). I did/do check the fluid levels of the batter and they were all good. It seems that everything is working the way it should. So, I guess my question is how long should a (fully charged) battery last is you only have two lights on inside the trailer?
  • With shore power hooked up:
    Measure AC input to converter.....could be fed from a Circuit Breaker or plugged into an outlet
    Good AC to converter then measure converter DC output....S/B 13.2V DC MINIMUM

    Good DC output then check 'reverse polarity' fuses....could be on front or back of converter...S/B 30A or 40A

    Reverse polarity fuses good..then look for an in-line fuse on battery positive cable....30A at least and could be a 'DC Circuit breaker' (small box with 2 studs/pos cable on studs----might have small reset button on side of box)

    Good fuses....check battery water levels and specific gravity of each cell
    S/B 1.125 (dead battery)
    Also check cable connections are clean tight--ESPECIALLY NEG cable ground to frame



    Getting battery recharged from dead state is important for battery survival so disconnect battery cables (MARK THEM FIRST) get it hooked up to portable charger and then you can do ALL Voltage testing from converter to battery pos cable with battery disconnected and charging on portable.
  • Chad/Jen wrote:
    Our battery seems to be dead, even though the camper has been plugged in and the battery connected for a week or so.


    Do you periodically check battery fluids levels? ... if not, that's the place to start.
  • Yup, you need to do some meter checks. Battery first with nothing running, battery with truck running, battery with shore power, converter output terminals.

    My battery went dead and I found a loose negative wire at the converter terminals. Converter was running full blast trying to charge, but the loose wire was just heating up and creating a high resistance load.

    If you can get to the positive and negative wires on the converter terminal strips, wiggle them and watch the 12 volt interior lights. If one is loose, the sudden connection will make the lights come bright.
  • Put a multimeter on it and see if its getting fed from the converter when you plug in you should see it jump up a few volts. if not id start at the converter (should have reverse polarity fuses somewhere in line)