Battery/Inverter issues

[Jimmy1040]

I have a 2017 Montana 3911FB with the residential style fridge. Whenever I unplug Ac power to travel I turn my Inverter which is a WFCO WF51510Hp on. It runs fine for only about 2 hours before it kills the (2) 12 volt batteries in parallel. Is this normal or do I have battery failure. I took both batteries out and charged them all day.
I’m thinking I have 3 options here
1. Replaced both batteries which are 2 years old
2. Getting (2) more 12v batteries and parallel all 4 batteries
3. Buying (4) 6v batteries and run them in series

It would be nice to be able to boondock or travel long distance with losing all the food in fridge!
If anyone has any advise for me it would be much appreciated

[airboatart]

When hooked to your TV and driving should keep the batteries charged

[PNW Fireguy]

if the two 12 volt batteries are the ones that came with your rig they may have about 100 amp hours between them of usable capacity. I am not too sure about the TV altenator being able to keep up with the draw on the batteries. I would recommend using 4 6V deep cycle batteries. Hook two each in series to produc e 12vdc and then connect those two strings in parallell to double the available amp hour capacity.

[AZ Traveler]

Jimmy,

First - welcome to the forum!

A battery monitor would also be very helpful. You may have other electric loads that are running your batteries down early. Even with small group 24 batteries you should get more than 2 hours. Your batteries may have been ruined by going below 50% several times.

[browens62]

Here is some battery information i found the other day, on lead acid

The dealer installed 2 group 24, so that give us half of the total amp hours, we do we only have 75 amp hour that is usable

After driving for 6 hour, everything was fine for us

In the future we will upgrade to 4 - 6 volt



SOME COMMON BATTERY SIZE CODES USED ARE: (RATINGS ARE APPROXIMATE)

U1 34 to 40 Amp hours 12 volts
Group 24 70-85 Amp hours 12 volts
Group 27 85-105 Amp hours 12 volts
Group 31 95-125 Amp hours 12 volts
4-D 180-215 Amp hours 12 volts
8-D 225-255 Amp hours 12 volts
Golf Cart & T-105 180 to 225 Amp hours 6 volts
L-16, L16HC etc. 340 to 415 Amp hours 6 volts

[Jimmy1040]

Yes I have drained them all the way down every time stored for 2 years.

[gjennings]

Originally Posted by Jimmy1040

Yes I have drained them all the way down every time stored for 2 years.

Lead Acid batteries should never be taken below 50%. Each time they go below damages them so you could have bad batteries. I would give them a full charge and have them tested.

[darrylwt]

Originally Posted by Jimmy1040

I have a 2017 Montana 3911FB with the residential style fridge. Whenever I unplug Ac power to travel I turn my Inverter which is a WFCO WF51510Hp on. It runs fine for only about 2 hours before it kills the (2) 12 volt batteries in parallel. Is this normal or do I have battery failure. I took both batteries out and charged them all day.
I’m thinking I have 3 options here
1. Replaced both batteries which are 2 years old
2. Getting (2) more 12v batteries and parallel all 4 batteries
3. Buying (4) 6v batteries and run them in series

It would be nice to be able to boondock or travel long distance with losing all the food in fridge!
If anyone has any advise for me it would be much appreciated

I went with 3 100ah Lithium batteries with 530 watts of solar and I am fine and never lose power plus lithium will charge in 2 hours from zero plus you can use all the 300ah unlike acid flooded batteries you can only use 50% of the ah,s...But not cheap but they will last for 20 years

[jeffba]

Ran a res refer on a trip for 13 hours. TV kept battery (yes only one dealer installed battery) charged.

If your batteries are being discharged until they die-- that is your problem. You have killed them.

Get a battery disconnect.

[D&D Young]

Check the voltage at the rear plug on your tow vehicle with it running. You should be getting a reading around 14.4. If not check the 7 way for broken / disconnected wires. If it is around 14.4 plug in and and measure voltage at battery. If it's not around 14.4 check umbilical cord on the trailer. If you get the 14.4 reading then you must likely killed your batteries.

[Arkware]

I have had similar experiences with my rig.

First, make sure the ice maker is turned off. It draws a tremendous amount of power.
Second, sometimes the up and down voltage from the TV will cause the inverter to shut down. (it thinks there is a sudden drop in available power) I've been able to turn it off then back on and continue down the road.
Thirdly, got tired of the above, and upgraded my batteries to 4 - 6 volt golf cart batteries. Now I can drive all day without any issue with the inverter. (and run the heater when needed, too!)

[summer home]

I have 2 gp 27 deep cycle lead acid batteries, my Ram has a 220 amp alternator, we run the inverter on the road for 7 - 8 hours with no battery issues........

[Jimmy1040]

Thanks for all the replies. I’m gonna go with the (4) 6 volt batteries!

[PNW Fireguy]

Originally Posted by Jimmy1040

Thanks for all the replies. I’m gonna go with the (4) 6 volt batteries!

You should be happy with the outcome of your choice. However do not discharge your new batteries below 50%. DOD, including while in storage. You may also want to invest in a good shunt and battery meter as the OEM LED lights provided are worthless.