Short-Bed-Dually
Active Member
When dry camping does anyone turn off the residential refrigerator and inverter for a few hours at night to save battery capacity?
Dry Camping With A Residential Refrigerator
- Thread starter Short-Bed-Dually
- Start date
thewanderingeight
Well-known member
I would think you would end up using more energy in total when you turn it back on the next day. If the doors aren't being opened often, the fridge does not have to work very hard to keep the temperature within the set range assuming a reasonable ambient temperature. The compressor is not running for very long during each cycle, and the fans aren't going to draw much power. If the fridge is left off though, when you turn it back on, the compressor now has to run for longer to try and make up the temperature difference that built up while it was off.
This is the same reason that during the summer, it's suggested you increase the temperature of your thermostat during the day while you are at work, but not to turn off the system entirely as you end up spending more energy in total as the system works overtime to remove all the heat that built up.
Depending on how much room you have, you could freeze a few gallon jugs of water to place in the fridge. This will help to keep the temperature from rising just like ice in a cooler.
This is the same reason that during the summer, it's suggested you increase the temperature of your thermostat during the day while you are at work, but not to turn off the system entirely as you end up spending more energy in total as the system works overtime to remove all the heat that built up.
Depending on how much room you have, you could freeze a few gallon jugs of water to place in the fridge. This will help to keep the temperature from rising just like ice in a cooler.
ILH
Well-known member
Wow - 70 hours on 4 batteries? I've got a residential fridge on my 2020 Landmark and I've been looking at ways to run the fridge the day before we leave (while the RV is in storage) - so that we can load it up and hit the road. My calculations so far for the lithium batteries (2 size 27) was about 30 hours max. However, cost is getting prohibitive.
Do your calculations account for running your batteries below 50% (possible damage on lead-acid batteries)?
I'm not claiming to be an expert - that's why I'm asking the questions.
Oregon_Camper
Well-known member
Have you ever really achieved this 70hrs? That seems like a tremendous amount of amp hours from only 4 6v batteries. What is the wattage of your inverter?
I’ve never come close to running the fridge that long. I’m just going off what the Victron gauge is saying I have left for power. The fridge for the most part pulls between 5-6 ah. I was amazed at the low power it consumes. The most I have run the trailer without hookups is approximately 9 hrs.
The batteries are 235 AH so I have around 400+ ah hrs to use.
The batteries are 235 AH so I have around 400+ ah hrs to use.
ILH
Well-known member
In reality you've got about 235 x 2 x 50% = 235amphours before drawing below the half-way mark (potential damage). I'm guessing your Victron is showing total amp hours to total depletion. Could be wrong...
Oregon_Camper
Well-known member
Rick...your math is incorrect. When you connect the 6 volt batteries together in series to produce 12 volts, only the voltage increase....not amps. So you only have 235 amp hours, when you combine two 6 volts batteries into a 12v solution. Now, you take those 2 "12 volt" solutions and now you wire them in Parallel, you increase your amperage...not voltage. Now you have 235x2 = 470 Amp Hours. However, as you only get to use 50% of your amp hours on any battery, other than lithium. Using your four 6v batteries, you get a total of 235 usable amp hours @ 12 volts.
boatto5er
Founding VA Chap Ldr (Ret)
It's probable that the inverter will shut off when your battery output gets below 10.5 volts. In reality, that will give you much less that 70 hours.
