Using a chest freezer and temp controller for battery temp control

[Locky]

Here in sunny Thailand we have an ambient temp daytime of 32 deg C, I was toying with air conditioning a small room for the lithium batteries when I build my home system, when it occurred to me to use a chest freezer with an external temp controller to keep a bank of batteries at an ambient of say 25 deg C.
Anyone done this already?
Can any of you think of any reasons why not please, would there be any vent issues or something like that?
Seems to me to be a pretty cost efficient and low power consumption way of keeping the batteries at the right operating temp.
Much appreciated
Edit:
I run a fermentation fridge for my home brew on a temp controller at 20c already so am familiar with the concept.

 

[Rider]

Yup.

For Camping

I wanted a small power system for camping, so I used a lot of information gleaned from Will's YouTube vids to put together a system. My main objective was to provide enough power to run a fridge and keep it compact. The Solar Charger: As I was walking thru BJs, I spotted a tiered toolbox that...

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[FilterGuy]

Here in sunny Thailand we have an ambient temp daytime of 32 deg C, I was toying with air conditioning a small room for the lithium batteries when I build my home system, when it occurred to me to use a chest freezer with an external temp controller to keep a bank of batteries at an ambient of say 25 deg C.
Anyone done this already?
Can any of you think of any reasons why not please, would there be any vent issues or something like that?
Seems to me to be a pretty cost efficient and low power consumption way of keeping the batteries at the right operating temp.
Much appreciated

The good thing about using a freezer as your battery box is that it is probably a lot better insulated than most other things. The other thing would be to use the smallest freezer that would fit your cells.... this will help minimize surface area that heat can seep in. As you say, this could significantly reduce the energy requirements.

A couple of things to watch for:
1) Condensation. My guess is you have a high humidity to go along with those high temperatures so every time you open the box you will get condensation at least on the coils.... probably on nearly everything. I have no idea how bad it will be but it is certainly something to watch out for. (Note: If you are willing to raise the temp inside the box it will help reduce the condensation)

2) Compressor Cycling.
If you are going to bypass the built in controls of the freezer, watch out for situations where the compressor kicks on again soon after it stopped.... this can damage the compressor.

 

[Rider]

1) Condensation.

I glossed over that the OP wanted to put batteries IN it. The small chest freezers don't usually have defrosters, so ice buildup from condensation is a big issue. Has to be defrosted regularly.

 

[FilterGuy]

I glossed over that the OP wanted to put batteries IN it. The small chest freezers don't usually have defrosters, so ice buildup from condensation is a big issue. Has to be defrosted regularly.

He wants to bypass the controlls and keep the freezer at ~25C... He wont get ice buildup but he takes the chance of things getting wet. Having said that, if he keeps the freezer closed up all the time, it might not be too bad.

 

[Deleted-User]

I recall some Inkbird controllers have a runtime delay to prevent overcycling, but consult the manual for certainty.

 

[Rider]

He wants to bypass the controlls and keep the freezer at ~25C...

Yeah, ok.... I'll go back to sleep now. Nebermind...

But yes, and external thermostat on a chest freezer is possible.

 

[rossfree]

I recall some Inkbird controllers have a runtime delay to prevent overcycling, but consult the manual for certainty.

I have an ink bird controller and it does have a delay... mine set for 8 minutes. If the power goes out and comes back on, it resets the timer so it never starts with the compressor under pressure. I use mine to take a freezer and keep it at refrigerator temps. Works great!

Ross

 

[Camginger]

Actually, the same thing could be done in colder climates by keeping the batteries from freezing ( with a very low consumption light bulb as an example,...) inside the chest freezer. At least, that's what I think.

 

[FilterGuy]

Actually, the same thing could be done in colder climates by keeping the batteries from freezing ( with a very low consumption light bulb as an example,...) inside the chest freezer. At least, that's what I think.

Yup! It could be used in conjunction with this: https://diysolarforum.com/resources/simple-indipendent-battery-box-heater.115/

 

[unsubscribed]

I registered to the forum to ask this very question. I'm in Phoenix, where it gets into the 110's in the summer. While the grid is up, I can keep my batteries cool in the house. But when the grid goes down, I'll need a way to keep the batteries cool.

It doesn't make sense to use a 600 W window A/C to keep my batteries cool in the summer. A cheap refrigerator chest set for its highest setting would be fine. Anyone have recommendations for a cheap chest 'fridge that can hold 4 battleborns? (Or maybe 6, for future expansion.) Since I'll be drilling holes in the fridge for cable pass thru's, I don't want a high end unit. (Since that will ruin its resale value.) I would run it off 120 VAC.

 

[Brewman]

As a home brewer I've done this many times.

 

[Brewman]

I registered to the forum to ask this very question. I'm in Phoenix, where it gets into the 110's in the summer. While the grid is up, I can keep my batteries cool in the house. But when the grid goes down, I'll need a way to keep the batteries cool.

It doesn't make sense to use a 600 W window A/C to keep my batteries cool in the summer. A cheap refrigerator chest set for its highest setting would be fine. Anyone have recommendations for a cheap chest 'fridge that can hold 4 battleborns? (Or maybe 6, for future expansion.) Since I'll be drilling holes in the fridge for cable pass thru's, I don't want a high end unit. (Since that will ruin its resale value.) I would run it off 120 VAC.

Build a wood collar so you don't mess up the freezer.

 

[unsubscribed]

Clever. I'm on walmart right now, trying to find a unit. What have you used? (I'm assuming compressor instead of Peltier.)

Edit: And I assume that a freezer is a better choice than a 'fridge? (Better insulation.) Although I don't need my batteries that cold. (But I can use a timer to modulate a freezer.)

 

[Brewman]

Compressor

 

[unsubscribed]

I'm seeing $200 units on Walmart that I can pick up in the store. Guess I'll head over tomorrow after calculating what kind of volume I need.

 

[Brewman]

Look up freezer temp controller. A johnson controller would work.

 

[Pyke13]

A inkbird controller plugged into an inverter would do the job. I used to use a small chest freezer as a fridge this way. Used less power than a fridge

 

[WYtreasure]

source for 120v efficient refrigerators

If you really want to save on electricity costs, you can always turn a plain old chest freezer into a refrigerator using a Johnson controller. Unlike a refrigerator, the coldness will stay inside when you open the top. Here's what it looks like: Welcome to the party escheie. You're COOOL ?

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[hidiyguy]

I've used an inkbird controller to keep a freezer at refrigerator temps as a keg tap, and to use as a fridge in a trailer. Works great. As others have said, only worry I see is condensation that will occur inside the freezer/fridge compartment. Otherwise, it's a good efficient way to keep a small space cool if that is required. I captured energy use A 3.1 cu ft freezer was using around 300 Watts a day to stay at refrigerator temps of about 38 degrees in daytime with air temperatures of 90 and night time of 70. By contrast, a small dorm size refrigerator (also about 3 cu ft) was using over 1,000 watts per day to do the same thing. Chest freezer conversion is much more energy efficient.