2018 original battery - done?

SeaLaVie

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?

pthomas745

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!

Sharon_is_SAM

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.

SeaLaVie

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.

AnOldUR

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 ).

edit:
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.

Sharon_is_SAM

@AnOldUR - the 400s come with 200+ Ahr batteries pre-installed at the factory.

Denny16

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.

Cheers 

SeaLaVie

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_SAM

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?

SeaLaVie

Yes, I replaced it with a AGM 200ah from Renogy. Whew those things are heavy!

Denny16

Yes, yes they are, weighing in around 200+ lbs!
Glad you got it sorted.
 Cheers 

peterjoce400

Just opened the battery box on our 2019 400 (new to us in 08/2018) to see what was going on.  That is one crazy set up!! To need a whole afternoon to dismantle, replace and rebuild battery containment is nuts. At any rate one of the 6 vlts. is holding while the other seems to be toast with a faulty cell.  The brand installed is unknown to me.  Will replace with 1 12 volt as have that at hand.  Sadly, we also determined no voltage off the 2 100 watt solar panels so they need replacing as well which is disappointing as I understood they had an expected life of at least  10 years.  Suspected this since our summer road trip over the prairies in sunshine and we were not getting recharge while not plugged in.  I see Renogy has flex panels 100 watt.  Anyone switched over to those?

Denny16

How did you test your solar panels.  We have the 193-watt Sunflair Solar panels, which in max sun can put out 36VDC.  Do you have the Victron Bkue MPPT 75/15 solar controller?  If so, the smart phone application has a control to,shut off charging.  Check to make sure this is durned on.  Our panels were installed in Jan 2018, and are working just fine.
 Cheers 

peterjoce400

Denny:  measured the voltage on the roof.  No umph at all.  No Victron ( see photo): this controller markets from China at $20. purchased in bulk (oem).  Photo shows the voltage while plugged to shore power, once unplugged drops right off (which we now trace to the dead 6 vlt battery) but also continuously shows the night setting even bright sunlight and no power generated. 

DenisP

@peterjoce400 I replaced the two 100 watt solar panels on my 2018 400 after they failed with two Renogy flexible panels.  They have worked out very well.  The installation was pretty straight forward with the exception that the Renogy panels are the same width as the originals but are longer. I spoke to Austin at NuCamp about their method of removing the factory panels and I was concerned about possibly damaging the finish on the roof so I decided t install the Renogy panels over the factory panels and made an extension panel out of Lexan.  The idea is that should the Renogy panels fail in he future they could be removed easily without any contact with the bare roof.  I installed the panels May 2021 and have travelled about 15,000 miles since with no issues and better solar gain with the Renogy panels than the original factory panels. The middle pic is the final installation. Hope this helps.  

Take care

peterjoce400

That is really helpful. I had wondered about mounting over the existing as well so that is great to know.  Thanks for the reply with pics!

JamesC

I also have a 2018 tab 400 that came with the two six volt batteries. Towards the end of last year they were beginning to fail. Just replaced them with the Renogy 200ah battery. I also updated my WFCO panel to Lis module with the switch to enable charging of lithium batteries. So far let’s all working well and was worth the time and effort. I did delete the battery box!

Jax0913

@JamesC thanks for sharing! Are you happy with the Renogy? I have been eyeing it for a while, my only hesitation is the 2000 charge cycle lifespan. I like the built in bluetooth since I already monitor my panels with the Renogy home app. I was just comparing with the LI Time 200amp hr LiPO4 https://www.litime.com/products/litime-12v-200ah-plus-lifepo4-lithium-battery-with-200a-bms-max-200a-current-2560w-load-power?currency=USD&variant=43673568116956&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping&gclid=CjwKCAjwzuqgBhAcEiwAdj5dRnKoG4CyHINLN6LyGv2UQ-KV22rnPhJCTkj1O5_YMouPUPKZ-NPozBoCphYQAvD_BwE

Is it necessary to upgrade the WFCO Panel? I've read mixed info on the forum. 
Thanks! 

JamesC

it is necessary to change to a converter/charger that supports lithium charging if you want to take full advantage of your new, expensive battery. I went with the one with the switch instead of automatic sensing of battery type because of reports of problems with them not sensing correctly. I also do not plan on switching back to lead acid batteries so a hardware switched panel was fine. 

So far everything is working fine. First camping trip is a few weeks away but I have been monitoring the battery regularly. I also installed a new Renogy solar controller and that is working as well. 

Horigan

@Jax0913
Regarding LiFeO4 charge cycles.  Note that the 2000 cycle number is for complete 100% discharge cycles.  The way these batteries work is that this equates to 4000 50% discharge cycles, or 8000 25% discharge cycles, etc, in general.  Most of us are rarely getting close to fully discharging our batteries. 

That 2000 cycle number is low compared to the competition though.  I just bought two SOK 100Ah batteries from Current Connected.  Similar foot print to the original 6V with a good reputation, similar prices, and higher charge cycles.

Agree that upgrading the charger to Li compatible makes use of all the capacity.  If you have solar, you can just update the charge profile on that at first so it fully charges the battery above what the original converter/charger will charge to.

Jax0913

Awesome! That is helpful. Definitely below the competition for sure.

JamesC

A quick report on the new battery. 

First outing with the 200ah Renogy battery. With no hookups and no solar, we stayed three day and two nights with the Alde running (temps in low 30’s at night, high 40’s and low 50’s during the day), fridge, lights when needed and water pump at times. We made no effort to conserve but we never were wasteful either. Started the battery at 100% and it dropped to 60% with use. We could easily stayed two to three more days. This is a great improvement over the original AGM’s performance even when new. With adequate sunshine and my portable solar connected our limiting factor is likely to be the tanks. 

Denny16

My experience has been the gray tanks fills up sooner than any thing else, limiting out time out.  We are considering getting a portable tank to augment the TAB’s 400 tank.  Our battery system (20-Amp Hr AGM) keeps up with the solar charging from our factory 200-watt roof mounted panels.  Water is the limiting factor.  

Cheers