Battery Draining Issue

Lauinger

We have a 2020 TAB320S with a 24M-EFB deep cycle Interstate battery (new in May 2023). We also have a 100w solar panel for recharging.
We have never had battery issues until recent trip. Over the past 12 trips (4years) we’ll typically run battery to about 70% by lights out and get a full recharge quickly in the morning.
We typically run Alde and refrigerator on propane and use lights and water pump very sparingly. We’ll change phones using USB overnight.
We usually wake up to the same ~70% in the mornings with these utilizations.
On our recent trip we had the first three nights with normal experience as noted above. On nights 4, 5 and 6 we woke to capacities of 25%, 15% and 21%, respectively. On all three days we got full recharges to 100% with solar panel.
Does this sound like a faulty battery? Can that happen all of a sudden? Or is this possibly another source draining the battery at night or could there be a short somewhere?
We tested when we got home overnight with a 90%+ charge going into the night with the battery actually turned off to the camper. In the morning it was 21% again.
Any ideas? New battery?

marleecamps

I experienced the same thing last fall on an extended trip.   Battery (dual AGM 6 volt) simply didn't seem to hold a charge like it used to.  Took the opportunity to upgrade to single 12v 230 ah lithium battery.  Freed up 95 pounds of weight and expect to have much greater capacity.

Lauinger

Thanks. They said our 2020 model would have to have inverter replaced to accommodate lithium.

Grumpy_G

Seems unlikely that the battery failed within one year, unless it was repeatedly  discharged to sub 10V. Where are you getting the percentages from ?

I'd fully charge the battery on shore power, then put some heavier load on it (I use the fridge on 12V DC) and monitor the voltage. You should get at least 3 hrs before the voltage drops really low.

Lauinger

Thanks. Will try. Percentages are from our solar controller.

pthomas745

No, you do not have to change your "converter" for lithium.  Your converter will charge the lithium setup, but "only" to about 85 percent.  Your properly configured solar controller can handle charging a lithium completely. 

What exactly are you using to make these battery readings?  Which solar controller? 

Is the battery "rested" when you take these readings?  If a lead acid battery is being charged or discharged, the voltage readouts you will get with any device will be "false".  The battery must be "off".  No charging, no discharging.  Only then will the battery "rest" and the voltage settle down.  (You only need a few minutes for the battery to settle for our purposes...in a lab, they would "rest" for many many hours and then measure the voltages down into several decimal points.)

Trying to chase battery voltages without the lead acid battery "at rest" can be very confusing. 

Lauinger

Using Go Power Solar Controller.