I need to choose an inverter to keep refrigerator running

[grommet]

Can someone advise me on choosing an inverter? I have a 650 watt refrigerator and I need to keep it running when the power goes out. I have two 60Ah 12 deep cycle batteries and I am looking at a 2200 watt true sine wave inverter on Amazon. I cannot afford to make a mistake so would someone help and tell me if this would work? I am going to try and include the link to it, I am not sure it it will post.

This is something I have been worried about for a long time and have worked very hard on. Today the wheelchair repair technician came and installed two new batteries. I kept the old ones which I think are working at at least 75% capacity. Saving money using these, I want to get an inverter. I am also interested in knowing if my plan is a good one or needs to change. Here is the link, thank you very much.

https://www.amazon.com/gp/product/B...&pf_rd_p=ab873d20-a0ca-439b-ac45-cd78f07a84d8

 

[FreeDiver]

The inverter you're wanting to get will do the job fine for what you're wanting to do. The problem is gonna be the batteries. At 650 watts with 85% efficiency on the inverter. You are looking at 65-70 amps draw. With that draw, you're looking at about a 1/2 hour run time at best. Remember. If you charge(or discharge) batteries too fast. They build up internal resistances that can cause a loss of charge and heat up the battery. You really don't want to be putting a 60 amp load on a 60 ah battery. especially a used one.

What I would do is go to a golf cart shop and see of you can get any used golf cart batteries. Used batteries should cost about $25-50 apiece and you will need about 4 of then. With a 4 golf cart battery configuration. You should be able to get about 8+ hours of run time.

 

[oregano]

@FreeDiver, your math is slightly off. 650 watts = ~6.5 amps, not 65 amps. Roughly 100 watts = 1 amp.

As for inverters, lots of garbage out there, lots of worthless inverters from China that are more snake oil than an actual functioning piece of equipment. Be very very careful of any inverter that sounds too good to be true. Also, when a compressor kicks on it temporarily doubles the power draw. @grommet will need an inverter that has the peak power rated at about double the steady power. Another thing to do is to put a power strip in between the freezer cord and the wall outlet. A power strip has no surge protection, so it is less likely to overheat. Turn the fridge on maybe twice a day to keep it cold.

 

[FreeDiver]

@FreeDiver, your math is slightly off. 650 watts = ~6.5 amps, not 65 amps. Roughly 100 watts = 1 amp.

I was giving a load calculation for the 12 volt input on the inverter. Not the 120 volt output.

 

[grommet]

The inverter you're wanting to get will do the job fine for what you're wanting to do. The problem is gonna be the batteries. At 650 watts with 85% efficiency on the inverter. You are looking at 65-70 amps draw. With that draw, you're looking at about a 1/2 hour run time at best. Remember. If you charge(or discharge) batteries too fast. They build up internal resistances that can cause a loss of charge and heat up the battery. You really don't want to be putting a 60 amp load on a 60 ah battery. especially a used one.

What I would do is go to a golf cart shop and see of you can get any used golf cart batteries. Used batteries should cost about $25-50 apiece and you will need about 4 of then. With a 4 golf cart battery configuration. You should be able to get about 8+ hours of run time.

Thank you for your help.

The refrigerator is 650 watts but only while running. I do not know how much run time per hour it would have but it seems that most of the time it is storing the cold and not cooling. That is why I thought these smaller batteries could work but maybe not. I can't carry large batteries home and with the order to stay inside, I would need to order one online. There is an expensive 100Ah 12 deep cycle battery on Amazon, I think it is around $200.

If it would mean I need to buy a lot of batteries, I cannot do the project. It is too expensive for me. My other idea was to get a 12 volt refrigerator/freezer and use that. I found one I thought would be a good idea, it runs at 45watts. The reviews on Amazon confuse me however, with many people saying it is good and others saying it is terrible. I keep finding that with Amazon so I do not know how to choose things.

I am starting to think this project will only work with a lot of battery capacity. I cannot see how I could manage that.

 

[Lymle]

How about just taking a more simple approach & get a big ol thick insulated cooler & a booty load of ice?

Then just prioritize the important items to put inside.

My brother left his beer cooler in a closet, forgot it, then found it 2 weeks later.
He said they were still frosty.

Crazy

 

[grommet]

How about just taking a more simple approach & get a big ol thick insulated cooler & a booty load of ice?

Then just prioritize the important items to put inside.

My brother left his beer cooler in a closet, forgot it, then found it 2 weeks later.
He said they were still frosty.

Crazy

That's amazing. I didn't know that was possible.

In a power outage however, the elevators in my building will not work and I use a wheelchair. I cannot go out for ice. Still, it is great to hear how well a cooler can work. Maybe it could be a solution for planned blackouts, stock up on ice and wait it out. No batteries or anything else needed. I think the simplest solutions are the best, thank you for the very good idea.

Do you have a suggestion on a good foam cooler? I have never had one. Does Amazon sell them?

 

[Lymle]

That's amazing. I didn't know that was possible.

Knowing my brother, he probably added an extra week to flare up his little "lost beer story"

I think the simplest solutions are the best, thank you for the very good idea.

●‿● Every once in a while I have one of those.

Do you have a suggestion on a good foam cooler? I have never had one. Does Amazon sell them?

Hmm
Honestly, I couldn't tell you.
But It would seem to me that you could probably beef up just about any coolers cold retaining capacity by adding more insulation yourself...like a big thick blanket or something...maybe a couple.

Prolly what my brother did to his beer cooler.

 

[disconnected]

Do you have access to a patio or deck? I actually just brought home a very quiet and small gas generator. It puts out 1,000 watts.

 

[grommet]

Do you have access to a patio or deck? I actually just brought home a very quiet and small gas generator. It puts out 1,000 watts.

I do not. I need to solve the problem another way. I keep going back and forth between choosing a DC 12volt refrigerator/freezer and using and inverter, maybe buying a 100Ah deep cycle battery on top of the 2 60Ah batteries I have.

The problem with the DC refrigerator is I do not know if the one I choose will be reliable. The reviews and testers are coming up with different results. I know my refrigerator works, so that removes the guesswork but the inverter is $339 plus another $200 for another battery. This is hard to solve.

 

[Thinx]

Hi Grommet, just about Amazon, my friend says go by the number of stars an item has, not by the reviews. Hope you find a useful solution to this.

 

[grommet]

Hi Grommet, just about Amazon, my friend says go by the number of stars an item has, not by the reviews. Hope you find a useful solution to this.

Thank you very much.

 

[Thinx]

Hi again, also, you probably already know this, but advice for a power cut is that food will stay frozen for 24 hours in a half full freezer if you don't open it, or 48 hours in a full freezer, so if you don't open it in a power cut your food will be fine and stay frozen unless the power was off beyond those time periods, which is fairly unlikely?

 

[grommet]

Hi again, also, you probably already know this, but advice for a power cut is that food will stay frozen for 24 hours in a half full freezer if you don't open it, or 48 hours in a full freezer, so if you don't open it in a power cut your food will be fine and stay frozen unless the power was off beyond those time periods, which is fairly unlikely?

I did not know that. It is good to hear that my food would stay cold. The last time the power went out I had a mostly empty refrigerator and my icepacks softened and warmed up quickly. Now my freezer is stuffed full including a frozen one gallon bottle of water. In the refrigerator I have about five gallons of water and very little food.

It is the icepacks I am trying to keep frozen, I need them for back pain at night. I am going back and forth between keeping the refrigerator running and using a 12 volt freezer instead.

 

[FreeDiver]

It is the icepacks I am trying to keep frozen, I need them for back pain at night. I am going back and forth between keeping the refrigerator running and using a 12 volt freezer instead.

If it's ice packs that you wanna keep frozen during a power outage then I would recommend getting one of those top load freezers. If space is a premium. You can get small units that are no bigger then a washing machine. The nice thing about top load freezers is that it can keep things frozen for up to a week without power and because they open from the top instead of the front. You lose a lot less cold air every time you open it. BIM: That you will have to bend over and reach inside to get to stuff and that might be a problem if you're having back issues.

 

[grommet]

If it's ice packs that you wanna keep frozen during a power outage then I would recommend getting one of those top load freezers. If space is a premium. You can get small units that are no bigger then a washing machine. The nice thing about top load freezers is that it can keep things frozen for up to a week without power and because they open from the top instead of the front. You lose a lot less cold air every time you open it. BIM: That you will have to bend over and reach inside to get to stuff and that might be a problem if you're having back issues.

They can really keep things frozen for a while without power? That would be great, as long as the power was only down for a day. During the outages they didn't last more than that. It may be too much to ask but could you recommend a model on Amazon?