Battery Not Holding Charge

Canyoneer

We have the factory original Interstate Battery in our 2021T@B 320 CSS Boondock edition.  We discovered on our last camp trip the battery will not hold a charge.  The solar powers it up fine, but even without running anything but the water pump it goes from full charge to poor in a couple of hours.  We usually hook up to shore power on our trips.  This was only our 15th or so night boondocking so we're kind of surprised the battery is possibly kaput. Anyone experienced this?  Do  we have a poor grade factory installed battery?  Any tips on how to handle this are appreciated.  Cheers.

Sharon_is_SAM

Not unusual for a dealer installed lead acid battery to fail after 3 years.  You don’t say how long you Boondock, but, many casual boondockers get by with a 100 AHr battery.  AGM will get you at least 50 AHr and a lithium battery will get you almost 100 AHr of use.  

Grumpy_G

Fun fact about Interstate: They don't make batteries, they are a marketing and distribution company. They have quality marketing

From what I've seen RV deep cycle lead acid batteries seem to not last long when they are constantly on a charger and not cycled on a regular basis. With the prices of LiFePo batteries having come down a lot that's what most people use as a replacement.

elewis33

I'm curious if the trailer companies tell people that the lead acid batteries can only be used down to 50% of their stated capacity? For people that plug in whenever they camp it's not a problem. But a totally different story for those that boondock.

Marceline

Canyoneer said:

We have the factory original Interstate Battery in our 2021T@B 320 CSS Boondock edition.  We discovered on our last camp trip the battery will not hold a charge.  The solar powers it up fine, but even without running anything but the water pump it goes from full charge to poor in a couple of hours.  We usually hook up to shore power on our trips.  This was only our 15th or so night boondocking so we're kind of surprised the battery is possibly kaput. Anyone experienced this?  Do  we have a poor grade factory installed battery?  Any tips on how to handle this are appreciated.  Cheers.

1. Are you running the fridge?

2. When storing the camper, have you been turning the battery switch to the "off" position?

3. During your boondocking expeditions, have you ever run the battery so low that the CO/LP detector alarm goes off or the lights start flickering?

4. Have you installed the Victron Connect app on your phone to monitor your solar output and the charge on your battery?

Sharon_is_SAM

@elewis33 - I think that that is part of the learning curve with campers.  You need to invest some time learning about 12V systems.  You can use AGM batteries more fully, but, it will shorten the life of the battery.  I think if I only camped using shorepower I would get a cheap battery and plan on replacing it every 2-3 years.  

pthomas745

I say the same thing when battery questions come up.

1.  What are you using to monitor the battery? Victron app?  Multimeter? The "meter" inside the trailer?

2.  Whatever the device you are using, is the battery "rested" when you take this readout?  I mean: is the battery switch off, no charging coming into the trailer?

If a lead acid battery is not "at rest" when you take a readout, and the battery switch is on: the battery is being "discharged".  Even the parasitic drains of a trailer are enough to lower the "voltage reading" of a battery.  If the fan is running, or the fridge, the lower voltage displayed can be quite dramatic, and make you think the "battery is not holding a charge."  Any "voltage" monitor will show you this false reading, no matter which one it is: the Victron, or a multimeter, and, the meter inside the trailer.

The only way to determine a "reasonably" accurate state of charge of a lead acid battery is: with the battery switch off, and no charging coming into the trailer.  Until you can get that "stable", rested battery voltage reading, don't give up on your battery.  All the other advice in this thread is good, and bad things happen to batteries when they are neglected by being run down "too low" too often.

So, get the battery settled down.  Tell us what you are using to monitor the battery.  The battery monitor in the trailer is literally always wrong. 

manyman297

Just replaced the AGMs in our 400 with LiTime lithiums (200ah). Time will tell about quality but we have way more usable power now. We’re able to easily run two refrigerators (the stock isotherm and an external 12v cooler) and keep the vent fan on all day. Solar helps but isn’t as needed now. No more power anxiety. 

Mickerly

There are many variables not addressed. Are you towing with the battery ON (I hope)? If the battery is OFF or disconnected it is not getting charged from the tow vehicle. The refrigerator draws so little power, the tow vehicle will actually charge the trailer battery. The regular 320 with the propane refrigerator; no so much.

The NR741 refrigerator should use 3amp/hr max. As a general wag, I plan 5amp/hr for the trailer unless I stuff the freezer with frozen ice bottles and turn the refrigerator OFF. As stated above, I try to stay less than 50% discharged. Our 2018 doesn't have solar while your '21 does.

The model of Interstate Battery makes a big difference. As mentioned, they don't make batteries. Some of their labeled batteries are very good, some not so much. Their line of AGM RV Marine batteries seem to be pretty good.

Modern batteries don't like constant charging. Our WFCO power center constantly charges the battery. It would be better if it allowed the battery to discharge about 10%, then pump it back up. If you leave you trailer plugged in at home between trips, you will  shorten the battery life. An AGM specific charger or "maintainer" it a better method of staying both charged and healthy; although, your solar panel should keep it charge.