Commercial fridge batteries keep dying

[Judemaster]

We have 2017 heritage glen with a commercial fridge. We presently have 2-12 volt batteries and inverter to run it when boondocking. We have to recharge the batteries every 6-8 hrs. Does this seem normal? Are there other batteries that would be better? I was thinking of my dads golf cart and getting 3-4 of those. Suggestions?

[Flybob]

If your 12V batteries are the generic ones that come with an RV, they are really not made for boondocking with a residential fridge without solar or other charging. If you are going to boondock with a residential fridge, I recommend 6V golf cart batteries in series. You might even need two banks in parallel depending on how long you expect to be out.

[bikendan]

Yep
Two cheap dealer-installed marine batteries are only going to give you what you're getting, with a residential fridge on an inverter.
2nd the 2or 4 6v golf cart batteries suggestion.

[Judemaster]

Could I put the 4 golf cart batteries in the front storage? Or do they need to go on the tongue?

[Flybob]

Not sure about space, but they should be as close to the inverter as possible as the current in the lines from the battery to the inverter is about ten times the 120VAC current being drawn from the inverter. ie a 1200W appliance running on the inverter output will draw 100ADC from the batteries.

[TGR]

If you are considering installing your batteries in a storage area of your RV, remember, wet cell batteries need to be installed in a battery box and vented outside. You don't want them venting into your storage area.

[The Newsoms]

Could 2 12 volts be replaced with 2 6 volts? Is there a big weight increase in swapping 12 v with 6 volt?

[camaraderie]

Originally Posted by The Newsoms

Could 2 12 volts be replaced with 2 6 volts? Is there a big weight increase in swapping 12 v with 6 volt?

Yes you can swap 2x12 with 2x6 wired in series. The weight difference depends on the size of the 12V batts you are replacing. At most about 35 pounds more vs, group24's and almost nothing vs. group31's.
Note that a failure in ONE battery makes a 6 volt system worthless while a 12V battery can still be used. I prefer to only use 6V configuraions of 4 batteries but lots of folks take their chances.
A pair of group 31's in 12V will produce approximately the same as a pair of golfcarts in series...roughly 210 amp hour at 12V . Measure space carefully before buying!

[pmsherman]

Originally Posted by camaraderie

......
Note that a failure in ONE battery makes a 6 volt system worthless while a 12V battery can still be used. I prefer to only use 6V configuraions of 4 batteries but lots of folks take their chances.
...........

While it's true that a failure of one battery in a pair of 12V batteries will leave you with one functioning battery, this rarely works in reality. When the first battery fails, it will immediately start discharging the second battery until both reach the same low voltage, usually around 10V if one cell shorted out. If this happens while you are in the rig and you see the lights dim or get some other indication there's something wrong with the batteries, you could disconnect the batteries and probably not damage the second one. It's more likely you won't discover this until after the pair of batteries have stabilized at the low voltage.

At this point, you are faced with the problem of determining which battery failed. You'll need to charge them individually to see which one has the shorted cell. After identifying the bad one, you can replace it but you'll now have two batteries that are different ages and possibly different capacities. This isn't a good thing to do when using batteries in parallel.

Six volt golf cart batteries are readily available at WM, Costco, automotive stores, and other locations. Since a failed 12V battery in a pair should cause both to be replaced, I see no disadvantage to using two 6V golf cart batteries as an alternative. My rv, as delivered from FR, didn't have the two 12V series connected house batteries wired to the rig to correctly balance the load on the batteries. Over time, this would cause the batteries to age at different rates because one battery was always the first one to be drawn on.

Phil

[Cypressloser]

Originally Posted by Judemaster

We have 2017 heritage glen with a commercial fridge. We presently have 2-12 volt batteries and inverter to run it when boondocking. We have to recharge the batteries every 6-8 hrs. Does this seem normal? Are there other batteries that would be better? I was thinking of my dads golf cart and getting 3-4 of those. Suggestions?

For boondocking or going totally of grid with a res. fridge you'll need something like we have (see sig.) or a generator - pick your poison. You need to figure out how much electricity you consume per day, this depends on your lighting, how often you open the fridge, hot water on gas or electric, etc. We pull between 200AH and 250 AH in through the solar system which is enough to power everything except AC., on a good day we run the water heater on electric in the morning or do laundry.

What ever you do, invest in a set of good batteries, either 6V GC type batteries or AGM. Watch out for the AH rating on the batteries, a 12V battery with a 230 AH rating lets you use roughly half of the rated capacity, 2 6V with 230 AH each still have the same 230 AH capacity that a single 12V battery has. But 6V batteries tend to have thicker plates and usually last longer than 12V batteries (newer, good quality 12V batteries are catching up).
If you don't want to go solar and need to rely on a generator, invest in a good 150AH plus charger and in (at least) 4 6V or 2 12V true deep cycle batteries with 230ish AH each.

Progressive Dynamics sells good stand alone chargers or you could invest in a Magnum or Xantrex inverter/charger.


Both, solar and generator, have advantages and disadvantages, initial cost and weight are somewhat similar, solar is dead quiet and you don't have to buy gas but running the AC is a stretch. Going solar involves more planning and is very labor intensive, it is also expensive to transfer to another rv - but it is quiet!

[Judemaster]

We’ve just been charging thru the electric cord to the campers inver I guess. Not directly to the batteries.