Tab CSS 320 Boondock Lite 2019 Battery Draining Fast

JulieQ

Our battery seems to be charging fine with solar, to full charge. But our last trip drained quickly. We came home with full charge then left it on over night to test and by morning it was at 1/3 with nothing running. (checked refrigerator and all outlets) We never go below 2/3 with the solar running while boon docking. Do we need a new battery? Or are there other things we should check. We are in Tucson and the battery has been out in our carport in what has been the hottest summer on record here. 

Bayliss

@JulieQ, what type and size battery do you have?

Considering that you are in Tucson, if it is a wet cell battery (i.e., not sealed), the first thing I would check is the distilled water level in the cells.  If you have a multi-meter to independently confirm the actual charge, that will give you a better idea of the charge level of the battery.  However, when you check it, be sure that you disconnect the battery from any sort of charging device (e.g., the trailer power center/converter, solar charger, trickle-charger, etc.) and don't check the battery charge level while the trailer is plugged in to AC power (unless you have first isolated the battery with the cut-off switch in the aluminum tub.)  Same goes with not testing it while your seven-way plug is connected to your tow vehicle.  After disconnecting the battery from any charging source, wait about 1/2 hr to an hour before checking the charge to get an accurate reading.

(NOTE:  Although the USB and 12V cigarette lighter type outlets are powered by the battery (or, via the WFCO power center converter, which converts 120V AC to 12V DC power), your standard electric plug outlets are only powered by 120V AC when the trailer is plugged in to shore power at your home or campground.  If you are testing for battery power to the refrigerator, make sure that you have selected the 12V battery as the power source.)

VictoriaP

“with nothing running”...unless you turned off the battery disconnect, there are actually quite a few things drawing power even when theoretically off.

That said, being down to 1/3 overnight would be a bit much even for the known parasitic drains. The heat in Arizona is known to kill batteries, sometimes in as little as a year. I’d take it down to your local auto parts place that offers battery testing.

JulieQ

We have the Centennial RV/Marine battery provided by our dealer. We have only had it nine months. Maintenance Free, Deep Cycle Power. So I don't think we need to check the water levels. DEC24MF 

JulieQ

Yes, Victoria. I agree. Last trip out we were boon docking for 4 days and with solar charging  battery power never went below 2/3 even with running music almost constantly, lights at night,charging phones, DVD player etc. The battery seems to charge fine, although it only charged 2/3 after 3 hour drive to our site with full solar (Arizona haha) That was our first clue something was up. Charged fully on the trip home then drained to 1/3 when we tested the battery over night. 

Bayliss

@JulieQ, I have the same battery and have not had any issues with it.  Taking it to an auto parts or Batteries Plus Bulbs store, as suggested by @VictoriaP, would be your best option.  I plan to upgrade my battery to a Group 27 or Lithium type battery when mine goes bad, but so far, so good for what I have needed.

VictoriaP

JulieQ said:

Yes, Victoria. I agree. Last trip out we were boon docking for 4 days and with solar charging  battery power never went below 2/3 even with running music almost constantly, lights at night,charging phones, DVD player etc. The battery seems to charge fine, although it only charged 2/3 after 3 hour drive to our site with full solar (Arizona haha) That was our first clue something was up. Charged fully on the trip home then drained to 1/3 when we tested the battery over night. 

I don’t know if it will help now, but longer term, a couple of things.

- It may be worth storing the battery inside the house between summer trips. Climate control makes a difference; my in laws are in Phoenix, and we actually discussed battery life the last time I was down there. Friends who left their cars & golf carts in carports rather than better insulated garages definitely went through batteries more frequently.

- I have a NOCO Genius charger on hand leftover from the days when I had a car that ate batteries. In addition to smart charging, it has a repair function, and the newest models are apparently even better with that. I stick it on my trailer battery a few times a year and let it work its routine. Hopefully it’s keeping my battery healthy; it has definitely made a difference with the starting battery on my current car.

If you need to replace your battery, look at upgrading it to an AGM (they handle heat better), and sizing up to a group 27 or 31. Or better yet, to a pair of golf cart batteries. The 12v fridge on the CS models does use a fair amount of power, and even with solar, you’ll do better with a bigger battery. A group 27 fits in the Boondock tub with no issue, and my AGM 27 has 105AH to work with versus your 75AH (as with any lead acid battery, assume only 50% of that is usable, though with AGM you can get away with a bit more).

Lithium is not the best choice for AZ summers unless kept in an insulated compartment. It runs hot under ideal conditions, and they really are sensitive to charging under severe weather extremes. That said, their light weight makes them easy to pull and store indoors between trips!

pthomas745

You cannot learn a lot about the state of charge of your battery with the KIB monitor in your trailer. There is simply not enough information.   You have 2/3rds of....what?  If you have the stock battery....you can use 40 amp hours.  1/3rd of 40 is about 13.  Which sounds......pretty normal.  With solar topping you off during the day, you would be hard pressed to use 40 amp hours during the night. 

And:  if you do not "rest" the battery...or turn as much as you can off inside the trailer....and let the battery "rest" for a while.....you will never get a good reading.  Again, what can 1/3rd of the battery mean? 

The good news is you are apparently taking good care of your battery, and thinking about its health.

You might want to think about getting one of the plug in meters that go into your 12v plugs and getting a "real" number compared to the KIB meter.  It still suffers from the "rested" battery problem ( and there are workarounds for that) but it will at least give you better info.

Try Jenn Grover's blog for the spreadsheet on what the actual power use of the different devices in the trailer are:  https://jenngrover.com/guilty-as-charged-rv-battery-use-management/

Here is a state of charge chart, and Jenn's older Tab appliance electricity use sheet.

JulieQ

P Thomas, thanks for your thorough reply.