Compressor fridge power useage

[paulj]

i have a compass avantgarde cv20 which has a compressor fridge.My query is when not on ehu will my 100w solar panel and 2 110amp leisure batteries be sufficient to run the fridge and other usual things .
Any advice would be appreciated

 

[Robert Clark]

When running our compressor fridge pulls about 6 amps, though it’s not always running.

A 100w solar panel will only give you about 8a at mid day if sun is high in the sky, so you’ll be using some battery power.

 

[Minxy]

Strong ... how long ... etc ...

Depends how long you are going to be off EHU, you'll get an absolute max of 55ah out of your lead acid batteries unless you want to knacker them (don't go below 50%) so a 100w solar panel may struggle to keep you self-sufficient for a few days, depending on what else you use and/or if you do any driving too to put charge back in them.

 

[chaser]

Depends how big the Fridge is, we have one that is about the same as a normal 3 way one and our 100w panel just about keeps it going when in sunny places , don't think it would in uk

 

[Richard n Ann]

We've got a 150w panel and a compressor cool box. It pulls about 2.5 amps and the panel if sunny easily kept up with demand, producing 9 amps in sunshine. The weak point was our single 100ah battery.

If it's sunny, and your fridge isn't too big and pulls only say 4 amps. I think you'll be ok.

Don't park under a tree

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[Sundowners]

Looks like you need a genny---???????---- but then I would say that!!!!!!!!!!
I did try to find the fishing smiley
Seriously----- it looks like you would need more solar and batteries to be able to stay off hook-up for long periods!!!!!
( I was serious about the Genny!!!!!!!!)

 

[scotzsue]

wonder how i will get on with my little compressor fridge box and no solar, unless you count the little attach to battery one from Halfords

 

[Richard n Ann]

wonder how i will get on with my little compressor fridge box and no solar, unless you count the little attach to battery one from Halfords

The compressor cool boxes are ok for a day or 2 if set on 3°c. Ours was set on -10c in a high ambient temperature so over night it hammered the battery.

 

[autorouter]

The fridge specifications will show you how many amps it takes when the compressor is running. But since it switches on and off intermittently, what you really want to know is the power consumption over a 24 hour period. This is usually given in watt-hours or kilowatt-hours per 24 hours.

To convert watt-hours to amp-hours, just divide by 12 (because it's a 12 volt battery). So for example if it's 300 watt-hours per 24 hours, that's 300/12 = 25 amp-hours per 24 hours.

The power output from a 100 watt panel is very variable, but on a good long sunny day you can get 6 amps for 8 hours, which is 48 amp-hours. But some days you're lucky to get 10.

With 2 x 110 amp-hour battery capacity, you should aim to only use 50% of that, ie 110 amp-hours.

So with all that information you can work out how long you can last without hookup. It depends a lot on the weather.

 

[Minxy]

Strong ... how long ... etc ...

Depends how long you are going to be off EHU, you'll get an absolute max of 55ah out of your lead acid batteries unless you want to knacker them (don't go below 50%) so a 100w solar panel may struggle to keep you self-sufficient for a few days, depending on what else you use and/or if you do any driving too to put charge back in them.

Just realised I didn't make it clear that it would be 55ah out of EACH of your lead acid batteries, ie 110ah in total.

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[paulj]

Thanks for all the replies will check the fridge out for daily amp usage then that will give me an idea of how I will do
Many thanks to you all

 

[jongood]

When running our compressor fridge pulls about 6 amps, though it’s not always running.

A 100w solar panel will only give you about 8a at mid day if sun is high in the sky, so you’ll be using some battery power.

View attachment 301911

How depressing is that - that someone thinks that people need an app to do basic division.

 

[Robert Clark]

How depressing is that - that someone thinks that people need an app to do basic division.

Some people don’t know how to convert watts to amps (hence the question in the first place) I guess) and I thought putting the screenshot of the web page may be helpful to the OP

 

[jongood]

Some people don’t know how to convert watts to amps (hence the question in the first place) I guess) and I thought putting the screenshot of the web page may be helpful to the OP

I'm not criticising you @Robert Clark, I just find it incredible that somebody thought it was necessary to write it - Oh Please! its volts x amps

 

[MisterB]

Perhaps they used an app to write the app ...

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[Robert Clark]

I'm not criticising you @Robert Clark, I just find it incredible that somebody thought it was necessary to write it - Oh Please! its volts x amps

The internet if full of apps and websites reminding us of all the stuff we were taught at school but never learned or remembered

Makes you wonder what would become of society if one day there was no internet

 

[tonyidle]

When running our compressor fridge pulls about 6 amps, though it’s not always running.

A 100w solar panel will only give you about 8a at mid day if sun is high in the sky, so you’ll be using some battery power.

View attachment 301911

Panels mounted flat on the roof in the UK will at maximum give less than 60% of rated output. 5A is about the best you can expect for a 100W panel.

 

[autorouter]

How depressing is that - that someone thinks that people need an app to do basic division.

It's a nice simple project for a beginning web site programmer. Then when you've got it working, you might as well add it into your web site rather than throw it away. Somebody might find it useful.

 

[vicdicdoc]

I'm not criticising you @Robert Clark, I just find it incredible that somebody thought it was necessary to write it - Oh Please! its volts x amps

We're not ALL experts on electricity

 

[tacr2man]

Trouble is there isnt an app to be able to change a light bulb , you have to do it yourself , thats where the system breaks down .

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[EuroTrotters]

i have a compass avantgarde cv20 which has a compressor fridge.My query is when not on ehu will my 100w solar panel and 2 110amp leisure batteries be sufficient to run the fridge and other usual things .
Any advice would be appreciated

Is it a 12v Compressor fridge or are you running a 240v mains through Inverter ?

 

[MyrtleGuru]

How come so many manufacturers are fitting these fridges these days? They only seem suitable for people who use EHU.

The 3-way ones seem to offer much more flexibility.

 

[jongood]

We're not ALL experts on electricity

This is basic maths - volts x amps = watts

 

[MANGOFORTH]

Im interested in this topic!! I've been speaking to photonic universe regarding this. I sadly have not yet had the time to get my head around electrics and the maths involved. BUT I put It to PU, their response was, a 230v AAA+ fridge ran through correct sized inverter... Is more efficient than 12v equivalent. I have them a few of options, that's what they came back with... Not sure if this is helpful of relevant, but just putting it out there....

 

[Lenny HB]

Panels mounted flat on the roof in the UK will at maximum give less than 60% of rated output. 5A is about the best you can expect for a 100W panel.

I think you are working your figures at the wrong voltage a 100 watt panel absolute maximum is 6 amps. Need to do calculations at 16.5/17v.
My flat mounted 100 watt panels achive 5.5 to 6 amps a couple of hours either side of midday around the 21st June fall off quite a bit once you get away from those times/dates & we live on the south coast.

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[Top Hat]

How come so many manufacturers are fitting these fridges these days? They only seem suitable for people who use EHU.

The 3-way ones seem to offer much more flexibility.

I like them for 3 main reasons. 1/ switch it on and forget, like your fridge at home very little goes wrong with them. 2/ when on ehu you use the elec paid for not your gas, and when wild camping free solar. 3/if you have a pvc van the fridge can be installed at eye level because it slopes at the back.
The down side is you need extra solar and batteries to accommodate it and not expect to go wildcamping in this country for more than a few days in one place in winter.
I have 300a/h of batteries and 220w solar and never fell below 12.6v off ehu in 2 months abroad in the summer.
My rule of thumb would be i would be happy wild camping with 200a/h batteries and 200w solar.

 

[autorouter]

I think you are working your figures at the wrong voltage a 100 watt panel absolute maximum is 6 amps. Need to do calculations at 16.5/17v.
My flat mounted 100 watt panels achive 5.5 to 6 amps a couple of hours either side of midday around the 21st June fall off quite a bit once you get away from those times/dates & we live on the south coast.

A 100 watt panel is tested for output in standardised conditions, so that you can fairly compare different brands of panel. These conditions are about what you would get in tropical conditions with the panel at 90 degrees to the sunlight. Mounted flat on a roof in Europe you are never going to get 100 watts from a 100 watt panel.

As you say, 6 amps is about the max you can expect. That's 6 x 12 = 72 watts. Over a long sunny summer day you'll maybe get 48 amp-hours at 12 volts, that's 48 x 12 = 576 watt-hours, so that's about half a kilowatt-hour. That's enough to run a fridge in theory, but for average weather conditions you're going to need twice that panel size to be confident that there will always be enough.

 

[tonyidle]

I like them for 3 main reasons. 1/ switch it on and forget, like your fridge at home very little goes wrong with them. 2/ when on ehu you use the elec paid for not your gas, and when wild camping free solar. 3/if you have a pvc van the fridge can be installed at eye level because it slopes at the back.
The down side is you need extra solar and batteries to accommodate it and not expect to go wildcamping in this country for more than a few days in one place in winter.
I have 300a/h of batteries and 220w solar and never fell below 12.6v off ehu in 2 months abroad in the summer.
My rule of thumb would be i would be happy wild camping with 200a/h batteries and 200w solar.

2/ applies to both types of fridge. The problem with compressor fridges is that in this country, in average Summer weather, and more especially early or late in the year when lights and maybe TV are eating your battery, you will need twice the battery and solar capacity that you otherwise would. And even then you'll struggle.

 

[GPW]

Im interested in this topic!! I've been speaking to photonic universe regarding this. I sadly have not yet had the time to get my head around electrics and the maths involved. BUT I put It to PU, their response was, a 230v AAA+ fridge ran through correct sized inverter... Is more efficient than 12v equivalent. I have them a few of options, that's what they came back with... Not sure if this is helpful of relevant, but just putting it out there....

For my small hobby van I bought an A++ table-top fridge for £75. Powered it from a Victron 500 Multi-plus inverter-charger (it has a 2W standby power usage!) and running I measured a 36W power usage from the batteries. So in my experience a decent house fridge is a great alternative and as a side effect you get off-grid 240V thrown in for free.

ETA: Other benefits over a 2/3 way (gas/absorption fridge) of course are:
1. It works at any parking angle
2. It has a thermostat so temperatures are consistent.

 

[Robert Clark]

One thing to consider with a compressor fridge is the noise.

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