269 kWh mini fridge.. How many AH draw from my 12v battery bank??

ywhic · July 2013

I am looking heavily at a 3.5 cu ft fridge for my cabin.. says $29/year on the EER and 269 kWh / year estimated..

How many amp would this draw on a 12v battery bank??

Simple math looks like..

269 kWh / 365 days = 0.73698 day. and then / 24 hours = 0.03074

Would that be like 3.1 amps from the battery bank per hour?? or 31 amps per hour??

Since I am skipping the A/C for now, I need a fridge and this had the lowest rating (and 58 good reviews..)

NorthGuy · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

There was a recent thread about this.

ywhic · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

The thread doesn't cover conversion to battery AH.. Interesting reading on different models though..

Cariboocoot · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

The energy rating is at 120 VAC. So dividing 269 by 365 gives you an approximate average 737 Watt hours per day. Divide by nominal system Voltage (12) and get about 62 Amp hours per day.

It isn't going to tell you the running Amps because that would require the running Watts. There is no duty cycle rating in this so there's no way of knowing.

Rybren · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Your calculations above are all based on kwh and you still need to convert to amps.

So... the draw is roughly 736.98 WH in a day or 61.5 AH in a day. (you need to divide the WH by the nominal voltage to get AH)

- I didn't check your math

Photowhit · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

I think I mentioned in the past, The ratings are based on an ambient temperature of 72-76 degrees, not 95 so your duty cycle(the amount the fridge runs) will be greater. The good news is you live in a sunny area and the "...amp would this draw on a 12v battery bank?" will only be when there isn't enough energy generated by your array to power it. Yet another reason to go ahead and hook up all your panels.

BB. · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

The refrigeration compressor will probably draw between 110 to 130 watts or so when running (probably around 50% duty cycle--depending on ambient temperatures).

Small refrigerators draw a lot of power for their size--nature of the beast (and few manufacturers use very thick insulation).

I was lucky and found a ~17 cu.ft. refrigerator that used a bit more than ~300 kWH per year.

The only way to get a really efficient (and cheap) off grid refrigerator is to convert a chest type freezer and you can get down below ~0.3 kWH per day (~110 kWH per year).

But then you don't have a freezer and you are "doomed" to having top access to your food--and having to move baskets around to get at stuff in the bottom of the "fridge".

-Bill

Photowhit · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Bill has a great idea, particularly with the high ambient temperatures. I don't think they cost much if any more, and there's a thread here some where, that most of the thermostats can be changed with out having to buy a special 'beer brewer' thermostat.

Here's the thread, mostly points to a beer brewer site;

http://forum.solar-electric.com/showthread.php?18035-Chest-freezer-to-refrigerator-conversion-w-o-new-thermostat&highlight=freezer+conversion

ywhic · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

So on the low side 61 amp per day. So a 220 or 440ah battery bank should be ok.

I forgot a watt is a watt..

I would do a freezer for $180 and keginator thermostat for $50. but with 1 week left and no address yet kinda makes ordering hard.

stephendv · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Have you checked energy efficient full size fridge freezers? Don't know if you get them there, but the german brands tend to be very frugal, e.g.:

149kWh/year with a total 10 cu. ft. capacity: http://www.bosch-home.co.uk/our-products/fridges-and-freezers/fridge-freezers/KGE36AW40G.html?source=browse
155kWh/year http://www.liebherr.co.uk/HG/en-GB/products_uk-hg.wfw/id-650059-0_36075-1

Here's a small "table top" mini-fridge which uses 64kWh/year: http://www.liebherr.co.uk/HG/en-GB/products_uk-hg.wfw/id-650056-0_35425-1

Photowhit · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Stephen, Those start at $2000 around here. So would be cost prohibitive, at least for me. I checked them out as I hope to replace my fridge in the next year or so.

stephendv · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Photowhit wrote: »

Stephen, Those start at $2000 around here. So would be cost prohibitive, at least for me. I checked them out as I hope to replace my fridge in the next year or so.

Ouch. $2000 buys a lot of solar panels

waynefromnscanada · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

WOW! Amazing power consumption specs on those German fridges/freezers!
May I ask - - - what excuse do other manufactures use for not matching - - no, not even coming anywhere CLOSE to these specs? Do they have some terrible fear of insulation? Do they not have access to insulation? Is North American and Chinese insulation that inferior to what's available in Germany? Are German manufactures perhaps not in the pockets f the electricity generating industry? What possible excuse could they use?
Oh! I get it! German electricity comes in 220 volts instead of 110 volts, thus otherwise identical devices use half the amps. Yeah, that's it! Hahahaha

Cariboocoot · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Truth is, most companies do not care how much power their products use. Efficiency in electrical appliances is a new thing, and only starting to catch on. To that end it's cheaper for them to 'adjust' the specs than make something that doesn't suck up the juice.

Europe has pretty high-priced power compared to the US, so it matters. But when you're plugging in to "cheap and plentiful" no one cares. Some companies brag about how much power their stuff uses! Ever seen vacuum cleaners boasting how many Amps they draw? Like that's a good thing? Never see any numbers on their CFM or inHg. How many times have you seen hair dryers extolling their virtues with phrases like "it's got 1500 Watts!"?

Truth is we need a different mindset on this continent. Not likely to happen though.

Photowhit · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Cariboocoot wrote: »

Truth is we need a different mindset on this continent. Not likely to happen though.

...or perhaps it's the joke that "They do Germans drink warm beer? - Bosch Refrigerators." Sorry I heard that a few years back...I'm sure they make a fine product.

Cariboocoot · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Photowhit wrote: »

...or perhaps it's the joke that "They do Germans drink warm beer? - Bosch Refrigerators." Sorry I heard that a few years back...I'm sure they make a fine product.

It's the English and Lucas refrigerators, Wayne.

BB. · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Lucas electrical systems for cars--"Prince of Darkness"

-Bill

stephendv · July 2013

Re: 269 kWh mini fridge.. How many AH draw from my 12v battery bank??

Can add Siemens, LG and Balay (Spanish) to the list of brands that also fall into that energy usage category ("A+++" it's called this side of the pond):

Some more examples here: http://www.appliancedeals.co.uk/l/fridge_freezers-a_plus_plus_plus_rated/1-2/26

We got the Balay for our cabin, 9 cu. ft. fridge + 3 cu. ft. freezer and it consumes 156 kWh/year. http://www.balay.es/catalogo-balay/frio/combinados/3KSP6865.html

269 kWh mini fridge.. How many AH draw from my 12v battery bank??

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