Forum Discussion

GaryS1953's avatar
GaryS1953
Explorer
Aug 30, 2017

Camper AND truck batteries dead

So Ive been pretty proud of my recent solar upgrade to the camper, but haven't really had a good workout with it. Fun just knowing everyday the batteries are being topped off and floating due to solar power. So it was quite a shock today when I stepped into the camper to do dome things to prepare for this weekends upcoming trip only to find I had no power and my digital gauge was dark. OMG. So I went to my truck to get tools and a DVM to check the level of charge directly off the bats, only to find the truck was also dead. I had inadvertently left the camper connected to the truck after towing it this past weekend to a local park to dump. My thought is that somehow the truck drained my batteries, even though they were being charged all day by my 320 watts of solar. How is that possible.

When I finally got my DVM on the batteries (2 6 volts in series) they were reading 7.75 volts. Have I killed them? Now I've got my camper plugged into 110 shore power and the converter is charging them and they were reading 8.8 as I came in to type this post. I jumped the truck and got it started, but is THAT battery now fried as well?

Any ideas why leaving the camper connected to the truck would kill all the batteries? Any thoughts on what I should do next. I appreciate any input.
  • KD4UPL's avatar
    KD4UPL
    Explorer
    Aug 30, 2017
    Leaving the camper hooked to the truck should have kept it charged with that much solar. Are you sure your solar system has output? I'd look for a blown fuse, bad connection, fried charge controller, or something like that. With a Chevy the truck plug is always live so the parasitic loads in the RV drained it too.
  • dave17352's avatar
    dave17352
    Explorer
    Aug 30, 2017
    You must have left something on in the camper. Where you parked where you solar panels where partially shaded. That can kill the output.
  • SidecarFlip's avatar
    SidecarFlip
    Explorer III
    Aug 30, 2017
    Even thought I have a TC and my battery isolator works fine, I still unplug my truck from the camper when it sits and length of time. Better safe than sorry.

    Your batteries may come back and they may not. Flooded cell batteries don't like being discharged past 50% of their capacity and heavy discharge usually (but not always) results in decreased capacity and plate sulfation. All depends on how old the batteries are and how many times you discharged them below 50% capacity.

    I run a SeeLevel battery monitor on mine so I can tell at a glance the state of charge as well as the battery temperature, which is an important consideration because when you have a heavy charge rate or discharge rate, the batteries heat up from the chemical reaction. I like to keep them as cool as possible by limiting the charge and discharge rates.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 30, 2017
    I assume you will find the solar stopped charging due to some fault or you left something on to drain the batteries.
    Often you will get one pass and the battery(s) will recover. Next time you might have to grab your wallet so find what happened.
  • Yeti_plus's avatar
    Yeti_plus
    Explorer
    Aug 30, 2017
    With a GM truck the charge line is always powered from the truck to the trailer, so the solar should also keep the truck battery charged as well.
    To avoid the trailer or camper from discharging my truck batteries (2 large expensive batteries!) I installed a relay that breaks the circuit from truck to trailer/camper. That way trailer/ camper won't drain the truck batteries and I can start the truck, always a good thing.
    I would suggest either a relay or an isolator on the charge line after you figure out why the batteries went dead.
    Brian
  • GaryS1953's avatar
    GaryS1953
    Explorer
    Aug 30, 2017
    KD4UPL wrote:
    Leaving the camper hooked to the truck should have kept it charged with that much solar. Are you sure your solar system has output? I'd look for a blown fuse, bad connection, fried charge controller, or something like that. With a Chevy the truck plug is always live so the parasitic loads in the RV drained it too.

    So far I've found nothing obvious. No blown fuses, and the Renogy controller was showing a good connection to the panels.
  • GaryS1953's avatar
    GaryS1953
    Explorer
    Aug 30, 2017
    dave17352 wrote:
    You must have left something on in the camper. Where you parked where you solar panels where partially shaded. That can kill the output.

    There's really not much to leave on. All lights are LED and were off, the fridge was on propane, furnace turned off. The camper was only sitting there for 2 days, and when I left it Sunday afternoon my battery monitor was showing over 13 volts. The camper has been parked in the same spot for 2 weeks before this. In fact my Aunt (who is an RVer) came to stay with us for a few days and we had her stay in the camper and use it totally on Solar and propane with no issues, parked in the sames spot.
  • GaryS1953's avatar
    GaryS1953
    Explorer
    Aug 30, 2017
    SidecarFlip wrote:
    Even thought I have a TC and my battery isolator works fine, I still unplug my truck from the camper when it sits and length of time. Better safe than sorry.

    Your batteries may come back and they may not. Flooded cell batteries don't like being discharged past 50% of their capacity and heavy discharge usually (but not always) results in decreased capacity and plate sulfation. All depends on how old the batteries are and how many times you discharged them below 50% capacity.

    I run a SeeLevel battery monitor on mine so I can tell at a glance the state of charge as well as the battery temperature, which is an important consideration because when you have a heavy charge rate or discharge rate, the batteries heat up from the chemical reaction. I like to keep them as cool as possible by limiting the charge and discharge rates.

    I have a battery monitor as well. Unfortunately I didn't look at it for the 2 days the camper sat there as I wasn't using it. The batteries DO seem to be coming back up, currently at 9.6, being charged by the converter. It's only been a few hours since I discovered this, and it's dark, so no solar charging currently. The batteries were new this year, and have never been below 12.4 volts since I installed my panels and charge controller.
  • GaryS1953's avatar
    GaryS1953
    Explorer
    Aug 30, 2017
    Yeti plus wrote:
    With a GM truck the charge line is always powered from the truck to the trailer, so the solar should also keep the truck battery charged as well.
    To avoid the trailer or camper from discharging my truck batteries (2 large expensive batteries!) I installed a relay that breaks the circuit from truck to trailer/camper. That way trailer/ camper won't drain the truck batteries and I can start the truck, always a good thing.
    I would suggest either a relay or an isolator on the charge line after you figure out why the batteries went dead.
    Brian

    Your idea of a relay or isolator makes sense, though I don't normally leave the truck and camper connected when I'm not towing, this was a fubar.

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