battery drain after trip.

Discussion in 'Power - Site Power/Batteries/Generators/Solar' started by Snowman, Aug 17, 2017.

  1. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    Hey Folks,
    Went on a three day camping trip last weekend with a fully charged battery and drove home about 3 hours to park PUP in driveway, all closed up. I was walking past the PUP this morning and heard a beeping coming from inside so I opened it up to see that the LP Gas detector was making the noise, the battery in camper was pretty much dead (battery is new - purchased about a month ago). I hooked up the BatteryMinder and it indicated "weak" and it's now charging.
    My question is this: what could have drained the battery? The sink was in the downward position so the kill switch was activated. The battery terminals were still wired, but is there enough of a drain to kill a battery in 4 days? Curious for some insight.
    Thanks.
     
    Last edited: Aug 17, 2017
  2. VTRailroadguy

    VTRailroadguy Member

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    Aug 19, 2015
    Northwestern Vermont
    If you were running off your battery for three days and the only charge it got was from towing it home, I bet it just ran down. Depending on several factors, the tow vehicle won't really charge up your battery, it's more to maintain it while traveling. An LP detector can run down a fully charged battery relatively quickly, so a battery with three days of camping on it wouldn't last long without a charge.
     
  3. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    Good info to have. Still new to this PUP thing, so I'm gathering my knowledge as things go wrong!
     
  4. jmkay1

    jmkay1 2004 Fleetwood/Coleman Utah

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    Oct 10, 2013
    Northern Virginia
    Yeah the lp detector has a parasitic power draw. So if you have not disconnected the battery or plugged the camper in at home it would discharge the battery fairly quickly especially if the battery wasn't fully charged before hand.
     
  5. roybraddy

    roybraddy Well-Known Member

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    Mar 23, 2016
    King George, Virginia
    Be sure to do some slow re-charging for a couple of days on your battery. Once they go below the 50% charge state it a big ole nail being driven into the battery coffin. Hopefully it will recover good for you... When doing the slow charges be sure to watch for boiling out of battery fluids...

    I have a simple 120V 20AMP Circuit setup where i park my Trailer. I just plug the shore power cable using a RV30A to 15A long Dog Bone adapter into this spare 120VAC circuit coming from the garage. Then it keeps the batteries up just fine using the on-board Converter/Charger setup until I need to use it again...

    Roy Ken
    [​IMG]
     
  6. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    I'm pretty sure that my converter won't charge my battery, even on AC. I do have a battery minder that I charge it up after trips, which sometimes can take a day or a day and a half, while also desulfating. This is the first time that I ever had the LP detector give me the battery warning though. When I fired up my voltmeter after I had it connected to the charger for about 20 minutes, it read about 11.8, so hopefully that wasn't low enough to drive a nail into my new battery!
     
  7. roybraddy

    roybraddy Well-Known Member

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    Mar 23, 2016
    King George, Virginia

    What i do is a quick look at the battery terminals with a inexpensive DC VOLTMETER. If the battery is fully charged it will read 12.6-7VDC across the two battery terminals...

    Then I hook up the trailer shore power cable to 120VAC Receptacle in the garage circuit. using the same DC Voltmeter connected to the battery terminal I want to see it jump up to 13.6VDC or higher when plugged in. This tells me the charge part of the converter setup is working...

    If you don't see this increase in DC VOLTAGE at the battery terminals then you obviously have something wrong... A bad converter/charger, No 120VAC reaching the converter/charger maybe a tripped 1120VAC Breaker etc..., bad connection between the converter/charger and the battery which might be a disconnect switch engaged ot bad terminal connections, maybe a blown in-line fuse between the battery terminal and the converter/charger terminals... Some of the newer trailer use a 12V Circuit breaker here verses an in-line fuse... Be sure the battery terminals is connected in the right order (Not Reverse Polarity connected)

    Since the whole 30A Trailer Power Configuration revolves around the 120VAC and 12VDC Power Distribution panel I watch this area like a hawk... I want it to fail at home where i can do something about it. Not out Creekside somewhere with no LOWES or WALMART close by haha...

    Roy Ken
    [​IMG]
     
  8. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    That's interesting, maybe I'm misinterpreting my manual. My model number (can't remember at the moment) of my converter does not have the "C" on it, indicating that it is not a charging model. However, I installed a switch controlled voltmeter just inside the door (wired into the porch light) and it reads 12.8 or so while on DC, but does in fact read 13.7 or so while plugged into AC. You're telling me that this means that it is charging my battery?
     
    Last edited: Aug 17, 2017
  9. JT2

    JT2 Member

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    May 20, 2008
    >> ...a switch controlled voltmeter just inside the door (wired into the porch light) and it reads 12.8 or so while on DC, but does in fact read 13.7 or so while plugged into AC. You're telling me that this means that it is charging my battery?

    --
    No, I don't think so. On DC, it's showing battery voltage and will fall off as the battery depletes from use. On AC, it's showing the output of the converter which is taking 115 VAC and changing it to DC voltage for your lights, water pump, etc. The meter has no way of knowing whether that DC voltage is getting to the battery. (That would take additional circuitry, wiring and controls which your camper may or may not have.)

    /JT
     
  10. mstrbill

    mstrbill Active Member

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    Mar 17, 2013
    Austin , Texas
    Except his TV is a Suburban which has a 40 amp Aux circuit. 3 hours even with the fridge running would have put a good charge back in the battery. Assuming of course that wire was connected to the post in the fuse box and the circuit breaker was installed.
     
  11. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    MstrBill - How to I verify what you're proposing? What should I be looking for?
     
  12. roybraddy

    roybraddy Well-Known Member

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    Mar 23, 2016
    King George, Virginia
    Most definitely charging your battery... The problem is if you only have a 13.6VDC 17-20AMP charging source it will take a long time to get your 50% charge state battery to a 90% or 100% charge state. (40 hours to get to 90% and 78 hours to 100%). if you are camping OFF-GRID you will want to have a smart mode charger that starts out with 14.4VDC charge and then after one hour drops down to 13.6VDC for an additional two more hours just to get to a 90% charge state whick will be almost full battery performance. You can do do around 12-14 of these 50% to 90% charge state before you have to a full 100% charge without doing damage to a deep cycle battery.

    This is what PROGRESSIVE Dynamics states in their operating manual on how long it takes to charge a battery using the DC VOLTAGEs listed below: "Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.

    14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.

    13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.

    13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."

    This is based on having 17-20AMPS DC current available for each battery in your battery bank... NOTE That Progressive Dynamics doesn't even list using DC Charge Voltages around the 12.0VC range as this would take alot more than 100 hours to achieve a 90% or 100% charge state.

    Most older trailer only use 13.6VDC as charging DC Voltage and one hugh downside to doing this is a 13.6VDC charge source may boil out your battery fluid so if this what you have it behooves one to do keep a close eye on your battery fluid levels when it it sitting for along period hooked up to a 120VAC shore power source. the smart mode chargers will drop down to 13.2VDC charge source when no higher charging is requires sitting in the storage mode. 13.2VDC greatly reduces the boiling out of battery fluids over a long store time. When something kicks in drawing more DC Current from the battery then the smart mode charger will jump back up to the 13.6VDC charge level... When the higher current requirement goes away then the smart mode charger will revert back to its 13.2VDC Storage mode.

    Hopefully all of this makes some sense. This is battery science at play here for deep cycle flooded batteries...

    When I purchased my new 2008 Starcraft RT14 OFF-ROAD POPUP That was the first mod i did replacing the single mode Conerter/Charger for a 60AMP Smart Mode charger setup to support my larger 12V batter bank I want to to install right away... It almost takes care of my batteries automatically but I still go through all of the scheduled checks out of habit. My 12V batteries have lasted full performance until last season where they don't want to hold a good charge anymore. getting 7 years out of those batteries is a pretty good deal I think...

    Roy Ken
    [​IMG]
     
    Last edited: Aug 17, 2017
  13. Boatnman

    Boatnman Well-Known Member

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    Jan 19, 2017
    western Colorado
    If you're getting 13.6v when on AC, your converter has a charger. (Unless the original converter has been replaced, it's probably a simple "normal mode" only charger. So, as roybraddy, said, be careful you don't boil out the fluid.)

    Disconnect the PUP from AC so the PUP is on battery power only. Use your multimeter across the battery terminals (or use your new voltmeter) to get the battery voltage . Connect the PUP to the TV, start the engine, and get the voltage again (using the same method you used to get the first reading). If the voltage goes up, it's coming from the TV. If the voltage stays the same, your TV is not providing any power. If your TV has a factory tow package, it will probably be charging. If the TV's wiring harness was added later, it may not have been connected to the TV's battery but can be.
     
    Last edited: Aug 18, 2017
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  14. Snowman

    Snowman Member

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    Jul 12, 2017
    Boulder, CO
    Thanks! I'll give it a try when I break the PUP down.
     
  15. rabird

    rabird Howdy!

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    Mar 3, 2006
    TX
    a Conv/off/Batt switch indicates the internal converter does not have the ability to charge the battery.

    You discharge the batt camping and further discharge while sitting (propane/CO detector), ideally you would have put a charger on the batt as soon as you returned from camping. With an external charger, disconnect one batt lead so it does not continue to discharge in storage.
     
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  16. Snowman

    Snowman Member

    71
    2
    Jul 12, 2017
    Boulder, CO
    I have the Conv/off/Batt switch on my converter.
     
  17. rabird

    rabird Howdy!

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    Mar 3, 2006
    TX
    page 9-84 2011 Suburban indicates that the 'charge' line and the brakes controll are not wired from the factory.
    https://my.chevrolet.com/content/da...t/suburban/2011_chevrolet_suburban_owners.pdf

    . Red: Battery Feed* . Dark Blue: Trailer Brake* *The fuses for these two circuits are installed in the underhood electrical center, but the wires are not connected. They should be connected by your dealer or a qualified service center. If charging a remote (non-vehicle) battery, press the tow/haul mode button located at the end of the shift lever. This will boost the vehicle system voltage and properly charge the battery. If the trailer is too light for tow/haul mode, turn on the headlamps as a second way to boost the vehicle system and charge the battery

    So check that the trailer batt voltage increases when connected to your running vehicle to determine if the charge line is active. I'd not expect much charging from this, the vehicle wiring is likely too small, the distance from the vehicle batt to trailer batt is LONG, the vehicle charging brain reduces alternator voltage, ...

    Fuse and brake controller harness may have been supplied with the new vehicle, the above section of the manual once stated to plug the fuse into slot ?? to activate the charge line.
     

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