2018 original battery - done?

SeaLaVieSeaLaVie Member Posts: 44
I bought my 2018 tab 400 in December 2019. I assume it came with the original battery. I don't recall discussing it with the seller.

Battery label:

I hane a victron smart shunt on it. I'm not sure exactly what to post but heres the amps and voltage readings for a 24 hr period. Seems like the battery cant maintain enough voltage even when power draw is reasonable. Then again I really have no idea what to expect.

Time for me to replace the battery?


  • pthomas745pthomas745 Moderator Posts: 2,992
    Not easy to see with the history here.  Is the battery switch "on" when you took these readouts?  A battery "in use" by items in the trailer can show some dramatic "swings" in voltage.  What was being used in the trailer between "20:56" and for those few hours where the voltage dropped?  Was the trailer "in use?"  If so, that reading is inaccurate.
    It does look a little flaky. 
    Get a stable battery reading.  Turn the trailer battery switch off.  If the sun is out, on the battery setting page of the Victron, you can turn the "Charger" off.  Wait a few minutes and take a screen shot of your Status page.  Turn the solar back on, or do whatever you need to do to put a charge on the battery.  Let it charge for a few hours, and then go back and go through the same procedure, and get another readout of the "rested" battery.
    You need to get some "stable" battery readings to figure out what might be going on.

    And, that is a pretty amazing battery! 240 AH!
    2017 Outback
    Towed by 2014 Touareg TDi
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,002
    Did you buy new?  I don’t ever recall seeing that brand of battery in the 400 models.  As I remember, nuCamp changed over to the dual 6V batteries within the 2018 model year.  If this was original, nuCamp may have run out of the Harris batteries and just substituted this.  There was a history of early battery failure with the single, large batteries.  First sign of a failing battery is rapid depletion/inability to hold a charge.  I agree with pthomas745.  I would turn off the battery switch, charge it thoroughly, then watch the BMV.  If it loses a charge without any phantom draw, it is on its way out.
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • SeaLaVieSeaLaVie Member Posts: 44
    Pthomas745, yes it was being used pretty lightly. I had some lights and a small fan going and the amp draw was maybe just a touch over 4 amps at the most and the voltage dropped down to about 10 volts for a couple of hours I think while it was under that load. The graph shows the amps in blue and the voltage in red. I will get some readings and see what I get.

    Sharon_is_SAM, I bought this trailer used in December 2019. I never discussed the battery with the seller. I just assumed this is the one that came with the trailer. I could be wrong about that though.
  • AnOldURAnOldUR Member Posts: 912
    edited January 23
    SeaLaVie said:
    I just assumed this is the one that came with the trailer. I could be wrong about that though.
    That's a huge heavy AGM battery at 142 pounds. I doubt that a dealer would install it in a new trailer unless it was a customer request. Hope that it's OK because it'll be a bear to remove (but I'm old and weak :s ).

    Thanks for the correction below @Sharon_is_SAM. Showing my lack of 400 knowledge. I thought that all nuCamp batteries were dealer installed and that 400's normally had two 6V's. Good to have the correct information.

    Stockton, New Jersey
    2020 nuCamp [email protected] 320S * Jeep Wrangler

  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,002
    @AnOldUR - the 400s come with 200+ Ahr batteries pre-installed at the factory.
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • Denny16Denny16 Member Posts: 5,304
    The original 2018 TaBs built before Feb/March 2018, all had a single large 240 amp.hr. AGM battery factory installed.  Up through Jan 2018 all were the single battery, located just inside the rear cargo door towards the front.  You can see the battery whilst looking in from the cargo door, or by lifting up,the pax side rear bunk.  Sometime in Feb/Mar they went to the two 6VDC batteries inside a black box in the same location as the single battery.  If you see a black battery box cover, then you likely have the dual battery setup.

    The battery cover used with the dual 6VDC batter6 setup on the late 2018 and 2019 TaB400s.
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
  • SeaLaVieSeaLaVie Member Posts: 44
    Well I was able to verify that the old battery was toast. After fully charging it and disconnecting Shore power, it looked okay with no load, the voltage was pretty stable around 12.9 volts. As soon as I turned my fantastic fan on high, the voltage dropped to somewhere around 9.2 volts! I don't remember the amp load but it was just the fan running. The voltage would climb back up again once there was no load, but it was essentially useless.

    I put a new Renogy 200 amp hour battery in and everything is now behaving normally.

    Thanks everyone for the input and info!
  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,002
    Well, it is typical that a battery voltage drops under load, but that seems extreme.  The problem with purchasing used is that you don’t have a full history of battery maintenance.  Did you replace with an AGM?
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • SeaLaVieSeaLaVie Member Posts: 44
    Yes, I replaced it with a AGM 200ah from Renogy. Whew those things are heavy!
  • Denny16Denny16 Member Posts: 5,304
    edited January 30
    Yes, yes they are, weighing in around 200+ lbs!
    Glad you got it sorted.
    2018 TaB400 Custom Boondock,  Jeep Gladiator truck, Northern California Coast.
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