Battery Not Holding Charge

RScottDickie

I have a T@B 400 2018 with the original dual 6V batteries in it. I find that the batteries will only keep the fridge running for about 8 hours before the batteries are too low and the fridge cuts out. I had them tested two days ago and the mechanic said they seemed fine. I cannot think what else it could be other than the batteries are not holding a charge. Any ideas? Also if I replace the batteries what would be a good replacement battery? Thanks

qhumberd

I have a 2019 and I am also noting less life in my dual 6V AGM Harris batteries. I am looking into a single LiTime 200Ah battery. It looks to be nearly the same size as 2 of the 6GV AGMs.

https://www.litime.com/collections/12v-batteries/products/litime-12v-200ah-lifepo4-lithium-battery?gad_source=1&gclid=CjwKCAjwlbu2BhA3EiwA3yXyu_S1hTdtust9rka-iaesiTvqgpVKtR-rJvW3mp20aFJmvCkQnESTDhoCCRkQAvD_BwE

My factory install looks like this and the dealer added a solar port on the driver side. I have no inverter but use a Renogy 100W portable panel with a charge controller.

Is this the same location in the 2018?

pthomas745

The fridge going away as the voltage of the battery drops is a very good sign that they are dying.  What do you have to monitor the voltage of the battery? Multimeter?  Not sure if your 2018 has a Victron solar controller with the app or not.

The batteries are 6 years old....and they have done their job.

Your options are: change out the dual 6V for another set of dual 6v of the same size.  With 225 ah batteries, you get about 135 "usable" amp hours.

Or:

Change to a single lithium battery of around 200 amp hours, which increases your usable amp hours to around 190.  Many owners have done this sort of thing.  There are many choices in this type of lithium and many owners have made the switch.

Welcome to the Forums!

 

RScottDickie

Thanks very much for your insightful critique, it is very helpful. I feel it must be the batteries failing but I am not sure why the mechanic that tested them said they were fine? My battery is in the same location as yours and in the same black box. 

Grumpy_G

Because mechanics typically do a "load test" which is more similar to cranking an engine for 5-10 seconds. It does not test the capacity of the battery though.

I have some old batteries in my shop that will put out 100A for a few seconds multiple times, but they they still only deliver 7AH when on a capacity tester.

manyman297

The batteries in our 2021 400 gave up the ghost this year so the fact that your 2018s are just now giving you issues is great…you got your monies worth. 

I replaced our batteries with two 100ah LiTime batteries. Two was cheaper than one bigger battery and I’m cheap so I went that route. So far they’ve performed great. The extra capacity no longer gives me anxiety on longer trips or when we don’t have enough sun for solar.

Marceline

RScottDickie said:

I have a T@B 400 2018 with the original dual 6V batteries in it. I find that the batteries will only keep the fridge running for about 8 hours before the batteries are too low and the fridge cuts out. I had them tested two days ago and the mechanic said they seemed fine. I cannot think what else it could be other than the batteries are not holding a charge. Any ideas? Also if I replace the batteries what would be a good replacement battery? Thanks

What kind of fridge do you have? Is it. 2way fridge (no propane) or a 3way fridge?

RScottDickie

2way fridge

junglerich

I, too, have a 2018 400 with the original batteries (no solar), and I am so confused by what I need to properly use/charge lithium batteries. Watching this discussion with interest.

RScottDickie

I paid for solar when I bought the T@B 400 but it cannot keep the battery charged or even seem to help much. I tested the battery today and contrary to the mechanics diagnosis it is very week at holding a charge. I think like many of you indicated, a new battery is probably the solution the solution. I have one vote for a LiTime 200Ah battery, any other suggestions?

pthomas745

You put in the new lithium battery.   The ordinary WFCO converter in your trailer will charge it up to about 85 percent on shore power.  For that last 15 percent of amp hours, you can: 

Add solar with a compatible lithium capable solar controller.  This will get you the best bang for your buck, especially if you like to camp without hookups.  The newer trailers have installed solar, or have portable panels.  A portable panel setup can easily be added to your trailer.

Or: install a separate lithium compatible charger inside the trailer that you can simply plug into any outlet and charge the battery.  Many different options for this, also.

This link goes to a comment from an owner who went through this same process, and was nice enough to share lessons learned and mistakes that were made. 

https://tab-rv.vanillacommunity.com/discussion/comment/197738/#Comment_197738

Last: is the "need" to change the converter to charge the lithium "properly".  This is maybe the most expensive option, and will require some work to replace the converters.  There are several options. So far, though, most owners would skip the converter swap and work on the solar or separate charger route.

NorthIsUp

I have a 2019 400 and replaced the OEM batteries in 2023 with lithium upon realizing that they no longer maintained a satisfactory charge. I purchased two Battle Born 100ah batteries in size GC2 so that they would be a direct replacement in size for the OEMs. 

This, plus everything else that people have mentioned about solar and a WFCO upgrade tops it off. It totally converted the boondocking experience.