Residential Fridge - battery power

In most cases the engine alternator is charging the house battery bank when traveling, so there should be no worries of draining the batteries.

Westend - Thank you so much for explaining this. We don't intend to dry camp. We just want it to be on while we are driving, possibly for a total of 5 hours. So if I understand correctly, that is possible if we monitor it closely. We did look up the Energy Rating - Tier 1/383 KWH. Thank you again!

I got curious so looked up the pertinent stuff.
Your fridge uses 1.1-1.6 amps at 115V. The spread in current is probably due to the icemaker and the defrost mode cycling. Assuming no icemaker running and defrost cycle shut down (best scenario), running current draw would be around 1.2 amp, depending on ambient temp. At 80f, the nfg. states a duty cycle of approx. 50%. The above translates to a daily draw of 14.4 AH at 115v. Taking into consideration the loss through the inverter and transfer to 12v, your daily draw would be 144 AH.

Your Energizer Marine batteries may have a 20H capacity of 90 AH. There are no rock-hard figures for this because it is a hybrid deep cycle/starting battery and cranking amps don't correlate directly to AH capacity. Assume it's close to 90AH capacity per battery, X3= 270 AH capacity.

The numbers say that you should be able to run the fridge for one day until reaching approx 50% of the state of charge of the battery bank, industry standard for sustaining durability of the batteries. This would be with NO other loads present. Plug in a crock pot and all of the numbers go away. Run those Energizers down to alarm trip on the inverter more than twice and you will be buying new batteries.

thegriffins wrote:
Thank you for responding. I hope I have all of the information you need to help me.
1. The refrigerator is Energy Star. It is a Frigidaire LFHT1817LB6 - 18.2 cu ft - The paper work says 6 amp / 115 volts.

2. The inverter is WIN - 12X20B3RT / output current amps up to 16.7 amps, peak output 70 amps, output continuous watts 2000.

3. We also have a solar panel

4. Batteries are Energizer Deep Cycle Marine/RV - RC180/12 volt / Marine cranking amps 840/cold cranking amps 675/E27DC. There are 3 of them.

6 amp is the maximum rating. What does the yellow Energy Star sticker state for yearly use in KWH?

Thank you for responding. I hope I have all of the information you need to help me.
1. The refrigerator is Energy Star. It is a Frigidaire LFHT1817LB6 - 18.2 cu ft - The paper work says 6 amp / 115 volts.

2. The inverter is WIN - 12X20B3RT / output current amps up to 16.7 amps, peak output 70 amps, output continuous watts 2000.

3. We also have a solar panel

4. Batteries are Energizer Deep Cycle Marine/RV - RC180/12 volt / Marine cranking amps 840/cold cranking amps 675/E27DC. There are 3 of them.

What Tex said. No worrys about hurting the batteries as a fridge doesn't draw much. To put it in perspective, your microwave draws about 14 times the current as your fridge does. Fridges are usually around 1 amp except for an instant at start up.

Hi,

Keep the battery bank use to a maximum of 50% discharge and they will be just fine. Going lower than that may shorten the battery bank life.

Keep in mind too, that the cost of the conversion you want, with a couple of extra batteries and an upgraded inverter, as well as the fridge, may not cost much more than the cost of a replacement Norcold...so it may be worth it to you to do it.:)

If and when our fridge craps out again, we'll be making the conversion too! Most of the time, we're plugged in, and only boondock, on the trip itself, so we can deal with cutting off the fridge for a few hours at a time, if we notice a battery drain.
If you dry camp a lot, you may want to rethink it.

Good Luck:)

As Tex says, there is a lot of information missing.
Lots of people have done it, and we did it too, though temporarily, when our Norcold was out of service. We bought a small dorm fridge, and it worked fine, plugged into our system. But also like Tex, we have a larger battery bank, and solar panels to help during the day. Heck, I can actually run the A/C for a short time....an energy efficient fridge should be nothing.

Once you get your numbers for the Inverter and batteries, you can calculate what the system will handle. Then, look for a fridge that will work within those parameters....though you may find that you will need to add additional batteries and upgrade our Inverter.

As far as the fridge's draw from the inverter hurting the batteries, I don't think that would be an issue, though you may find that the inverter trips off, if there is to much load, or it may be so close to the capacity, that the batteries just drain too fast to make the conversion worthwhile/

Good Luck:)

Is the fridge energy star? What size is it? What size is your inverter? How many and what type batteries do you have? These need to ne a known quantity in order to make an informed answer.

Ours is a Samsung rf197, energy star and our inverter is a 2.5kw Magnum MSW drawing from 4 6v 220ah batteries. Ours is plugged into the inverter circuit all the time and runs perfectly. It will run at least 24+ hours before the AGS kicks in and with our solar, it very seldom requires a generator boost.