Battery Life in Hours

theoldwizard1 wrote:

jpjulian wrote:
Our new Mobile Suites came equipped with two 6 volt batteries and a 1000 watt inverter.

Looking at a brochure, it appears that 5er has at least a 22 cu ft side by side refrigerator with bottom freezer. Very nice but those can draw up to 20A !

I also noticed that the manufacturer offer an upgrade inverter with 4 batteries ! I hope you won big at the casino because you will be spend your winnings on this upgrade !

I got kicked at the casino, but that's beside the point. It is a 20 cu ft fridge and if I read right is supposed to draw on 5 amps. The furnace was on and water heater on propane. The inverter is dedicated exclusively to the fridge, not to the tv or any other a.c. appliance, or so we were told. The batteries should have been fully charged, if I read the panel correctly, as this was our 3rd night of use since purchase and the prior 2 were connected to 50A.

Joe

A little more study prior to purchase would have alerted you to the residential fridge...issues. Two choices if you want to continue to dry camp, more batteries with a big solar system or install an RV fridge. Possibly to use only when dry camping?

20 amps, Wizard? Wow

If you plan on doing a lot of dry camping then having 4 6V batteries are necessary. I'd also opt for solar.

As crazy as this sounds, most residential refrigerators will keep things "cold" for 12-24 hours WITH NO POWER if the door(s) are closed.

Battery "life" is measured in reserve capacity, which is how long in minutes it takes a fully charged battery to reach 50% state of charge (about 12.2 volts) at a discharge rate of 25 amp-hours. A pair of typical flooded lead acid 6v golf car batteies have about 400 minutes RC, so less than 7 hours.

I inspected a Travel Supreme coach last year that was all electric; oven, stove, fridge. The heat was Aqua-Hot. It had 8-6V batteries, 2-2000 watt inverters and a 12.5kw generator. I'll bet that it would not go the night with the heat on.

Most RVs I have seen with residential fridges use a 4 battery setup. 2 batteries are the norm for units with a gas fridge. You should not need to upgrade the charger/inverter/converter. It is obviously big enough for the 120 VAC you need and should have no problem charging a couple extra batteries. Remember, when you are dry camping, there are a lot of other electricity draws. Watch TV? Satellite receiver box, furnace fan if it's cold, smoke and CO detectors, water heater control circuit, lights, maybe more stuff. 12 hours on 2 batteries sounds about right.

Residential refrigerators (AC only) are not the best setup for parking lot "camping". A friend simply uses a chest type cooler. Much cheaper than replacing batteries that are ruined by be being totally discharged often. She plugs in and enjoys her huge refrigerator at the campgrounds.

I'd try it again, just make sure the batteries are topped off at the start of the night. If you get a repeat then the batteries don't hold enough for your overnight use and look into adding the extra 2 batteries that theoldwizard mentions were an option at purchase.

turn off the ice maker function when using inverter power
check to make sure your water heater is OFF or on propane
is this a combo inverter & charger
or a stand alone inverter
IF stand alone be sure to turn off the circuit breaker for the converter

or you have an endless loop drain

my residential 8cuft only used 100w, aka 9 amps at 12v,

I don't buy into the 700w, statement
its hard to believe, that you are using more than 300w for fridge cooling, and it should be cycling, Not a continuous draw

jpjulian wrote:
.... As far as I am aware, the only 120v appliance running off the inverter is the refrigerator. I would think we should have more capacity than about 12 hours of use before the batteries go south. .........

Joe

Sounds like you already learned what to expect. The idea of getting more than 12 hours is wishful thinking.