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No power on battery alone

RamrodRamrod Member Posts: 164
in Battery/Electrical & Solar
Second trip on my T@b. I have no power when using battery alone. Battery switch is on. Fuse ok. Checked fuses and breakers on inverter. When connected to shore power meter says battery voltage is 13.2. I appreciate any ideas on how to figure this out.
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    NomadNomad Member Posts: 7,209
    So, is your meter blank when not connected to shore power?
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    RamrodRamrod Member Posts: 164
    Yes
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    ScottGScottG Administrator Posts: 5,477
    Am I correct in assuming all your 12 volt devices (lights, fan, water pump, etc.) work normally when you are on shore power?

    Did you measure the voltage right at the battery terminals? If so, what was it?
    2015 T@B S

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    RatkityRatkity Member Posts: 3,770
    If your battery voltage says 13.2 when on shore power, it's not your converter. I know you checked the fuses, but sometimes they don't look blown. The inside fuse in the converter should be 30A and the outside in-line fuse in the battery case should be 30A (both large flat blade). I know this is obvious. The less obvious is to check out wires to see if they have loosened up. Please remove the in-line fuse at the battery first! Don't want it to be a shocking experience! Next less obvious is to check in the black box under the T@B near the propane tank and battery bin. Pry it off with a screwdriver, it has a seal and can be stubborn. Make sure there are no loose screws and no bare wires grounding themselves. 

    After these things, then it's time to take it to an RV place to get it troubleshooted by a certified electrician.
    2017 820R Retro Toy Hauler from 2015 Tabitha T@B from 2009 Reverse LG Teardrop (but a T@Bluver at heart)
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    RamrodRamrod Member Posts: 164
    Update. I drove four hours with Norcold on. Left Norcold on for 9 hours and in the morning there was absolutely no power. The battery meter and all lights, etc were blank/not functioning. Drove nine hours and the same. Was on shore power for the night and in the morning when I disconnected it the battery voltage was 13.6 and everything seemed to be functioning well. Drove another 9 hours and when I disconnected the trailer from the TV, once again no power whatsoever. I just connected to shore power and everything is fine. I will go thru above checklist. Thank you.

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    ScottGScottG Administrator Posts: 5,477
    Are you running the Norcold on 12 volt DC power? You can only do that when you are connected to a running tow vehicle, and that running tow vehicle has an adequate 12 volt charge line hooked up to the 7-pin wiring harness. Even then, many vehicles struggle to keep up with the power demand, and the battery may still get depleted.

    Where and how are you measuring your "battery voltage?" Keep in mind that if you are plugged into shore power, the voltage you see is reflecting your converter output, not your battery's state of charge.
    2015 T@B S

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    RamrodRamrod Member Posts: 164
    I was not aware that I cannot run the Norcold on 12 V battery power while driving. I have to check the TV output (I have to find the discussion that addresses how to do it). 12.6 volts at the battery terminals now and on the wall battery meter after being on shore power about an hour.
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    ScottGScottG Administrator Posts: 5,477
    Sounds like we may have found the source of the problem--I'm guessing you may not have that 12 volt charge line (not all vehicles do).

    It does sound like your converter is working properly, everything is connected as it should be, and your battery is taking a charge. If the battery is able to hold the charge is another issue--I learned the hard way that repeated excessive deep cycling compromises the battery. Good luck, and let us know what you discover! 
    2015 T@B S

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    PhotomomPhotomom Member Posts: 2,217
    I had to have a fused wire run from my battery back to the 12v pin on the 7 way connector. You may not have it, or if you do the fuse may have blown. 
    John and Henrietta, Late 2016 T@B S Max in Western New York
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    RamrodRamrod Member Posts: 164
    I found the culprit. My TV was not charging rhe battery. Fuse is blow. Why? 
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    NomadNomad Member Posts: 7,209
    Which fuse - on the TV charge line or the one on the T@B battery or the one in the converter box?
    Are all three matched up at 30 amps?
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    RamrodRamrod Member Posts: 164
    edited August 2016
    On the TV battery charge line. 2011 Acura MDX. It was a 20 amp fuse.
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    NomadNomad Member Posts: 7,209
    Think from other threads that it should match the others - All 30s
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    NormfunNormfun Member Posts: 285
    30 on mine both TV and Trailer. 
    Norm & Pat. 320 S Outback Utah or somewhere else.

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    RamrodRamrod Member Posts: 164
    If I change it to a 30 amp fuse I have read the wiring may overheat.
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    NomadNomad Member Posts: 7,209
    What gauge wire do you have? The T@B has 30s, your TV should also or you will probably blow again. If you charge wire can't handle it, you should probably string a new one. But, I'm betting your wire can handle it and you can just plug a 30 in.
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    RatkityRatkity Member Posts: 3,770
    10 gauge wire is necessary for the TV charging plug. I also have 12V outlets directly wired in my truck cap. They are also wired with 10 g (with inline fuse).
    2017 820R Retro Toy Hauler from 2015 Tabitha T@B from 2009 Reverse LG Teardrop (but a T@Bluver at heart)
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    ScottGScottG Administrator Posts: 5,477
    edited August 2016
    Agreed. 10 gauge wire is rated for up to 30 amps. 12 gauge is for up to 20 amps. Ramrod, you are correct that you should not install a larger fuse unless you verify that the wiring is sized to handle it.
    2015 T@B S

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    RamrodRamrod Member Posts: 164
    edited August 2016
    It is a factory designed towing wiring for Acura MDX 
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    PhotomomPhotomom Member Posts: 2,217
    Out of curiosity, what does the 12v line from the car battery thru the 7 way plug feed in the T@B, besides the refrigerator? The 3 way fridge on 12v shouldn't draw more than about 14 amps per the manual, and if there's nothing else a 20a fuse would be appropriate. 
    John and Henrietta, Late 2016 T@B S Max in Western New York
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    VernaVerna Member Posts: 6,878
    @Photomom, it also charges the T@B battery while driving. The T@B battery has a 30A fuse as does the converter for the battery fuse. 
    Verna, Columbus, IN
    2021 T@B 320S  Boondock “The T@B”
    Towed by a white 2019 Ford F-150 4x4 Supercab, 3.5L V6 Ecoboost “The Truck”
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    PhotomomPhotomom Member Posts: 2,217
    Verna said:
    @Photomom, it also charges the T@B battery while driving. The T@B battery has a 30A fuse as does the converter for the battery fuse. 
    Thanks!
    John and Henrietta, Late 2016 T@B S Max in Western New York
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    ColoradoJonColoradoJon Member Posts: 415
    edited August 2016
    Photomom is correct, the fuses do not all have to match.  The TAB has a 30 amp fuse at the battery but that does not mean you will be drawing 30 amps through your 7-way charge pin.  If you are then you have an awesome battery charger/tow vehicle combo!  I imagine it will be much, much lower than that.  If you run the fridge on 12V while traveling then you might get close to 20 amps.  EDIT - I'm not sure if the fridge draws power direct from the tow vehicle.  More likely it draws from the battery directly, which in turn is charged by the tow vehicle.  That is an assumption, though.
    Jon & Angela | Florissant Colorado | 2017 Outback S
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    ScottGScottG Administrator Posts: 5,477
    Photomom said:
    Out of curiosity, what does the 12v line from the car battery thru the 7 way plug feed in the T@B, besides the refrigerator? The 3 way fridge on 12v shouldn't draw more than about 14 amps per the manual, and if there's nothing else a 20a fuse would be appropriate. 
    If I understand it correctly, the 12v line connects to both the battery and the converter via the junction box under the front of the T@B. You might think of it as three spokes with the junction as the hub. That's why it can run DC devices (like the fridge) as well as charge the battery. The DC power supply for the fridge comes via the converter.
    2015 T@B S

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    ChanWChanW Member Posts: 3,158
    Often the factory wiring doesn't have a high capacity (high ampacity) charge line. 

    The 20A fuse that Acura installed is probably the right size for the wire-size they installed.
    Ramrod said:
    It is a factory designed towing wiring for Acura MDX 

    Chan  -  near Buffalo NY
    2014 S Maxx
    2011 Tacoma 4cyl ... edit: 2022 Tacoma 6cyl - oh yeah! 

     A_Little_T@b'll_Do_Ya
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