AC Fridge In Campervan -.Power Consumption Test

[hairydog]

If getting into the fridge wiring is difficult, you could do that, but then you lose the option of using the fridge's temperature control.

As an aside, I once had a problem with a domestic fridge not being cool enough. It turned out that the light was staying on, and the heat of the bulb made a difference. The fridge thermometer was quite near the light (so you could see it easily)

 

[wildebus]

If getting into the fridge wiring is difficult, you could do that, but then you lose the option of using the fridge's temperature control.

As an aside, I once had a problem with a domestic fridge not being cool enough. It turned out that the light was staying on, and the heat of the bulb made a difference. The fridge thermometer was quite near the light (so you could see it easily)

That is the perennial question isn't it? How you know for sure a fridge light really goes off when the door is shut
I am tempted to replace the bulb with an LED one but in reality a waste of time and money considering it is on maybe 10 minutes a day tops (so changing would save what? 0.05Ah a day?). So maybe if it breaks I might?

The only real (and slight) annoyance I have with the fridge is the temp dial is too easy to move if food is pulled in and out next to it and rubs against it. Usually ends up going lower temp position and the food at the top of the fridge icing up a little as it is right by the ice box pipes. So need to find the 'sweet spot' on the control if there is one and mark it as an easy reset position (using a probe with an external temp controller could be handy in that situation as well?)
Had the same random temp issue on my Waeco coolfreeze with external slider control... Too easy to move when opening lid and half the time everything got frozen!

 

[wildebus]

@wildebus can you tell me what exact model inverter you used and a cheap place to get it?

I bought this specific inverter - Victron Phoenix 12/500 with a Schoko socket - Victron Energy inverter Phoenix connector VE Direct Schuko. 12 - 500 - 230 V: Amazon.co.uk: Lighting
Bought from Amazon as that was the best price and most reliable source. Meadotech is another good place to buy and similar prices but for some reason their direct prices are more than their shops on eBay or Amazon.
Also bear in mind Victron make for a wide market so you must chose the socket style you want. IEC (like a kettle plug): Schuko (euro plug) or UK 13A. I chose Schuko as the inverter was £20 cheaper than UK socket and the style didn't matter for my install.
Also make sure it is the 12/500, and not a 24/500 or 48/500 you are selecting (first number is the voltage in. A 12V system needs a 12V inverter)


OK. Just some review points as you will find inverters a lot cheaper than Victron. And Smaller Victron Inverters as well....


Why do I need a big inverter if the fridge only uses 35W?
The inverter has to cope with a big in-rush from the compressor. The 35W fridge can have an inrush more than 20x that number and it is the inverter that has to cope with that (same reason you use 6mm power cables on a 12V Compressor fridge that supposedly draws just 3A in use)
Note: The Victron 12/250 and 12/375 cannot deal with the high inrush level the fridge generates.

What about other cheaper 500W inverters that have a 1000W peak? That will do it then, yes?
Many inverters just don't deliver on their claims which it comes to peak performance. You may have to buy a few to find one that works!

Ok. Cheap 1000W inverter then?
Yup. That has enough power.

Pure or Modified Sine Wave ones?
I've only used PSW. I have no first hand experience of using a MSW inverter on a Fridge but seen enough reports to suggest it may not be the best option.


So ... Bearing in mind the above, if you are looking for an inverter for a fridge, there is the Victron 12/500 inverter or another brand/unbranded 1000W PSW inverter.
There will likely be little price difference between them, and when you add in the 5 year Victron Warranty; its silent operation and build quality, it is the way to go IMO.
If you wanted to buy Victron but also avoid the overload (the 12/500 is designed to work with a peak of 900W for 30 seconds, which is why it is still suitable) then you could look at the 12/1200 or maybe the 12/800 but they are significantly more expensive and way oversized in normal operation.


Finally ... There are other top brand inverters that will likely work as well as the Victron one, but I haven't tried them so can't suggest or comment on those.

 

[Fletch6]

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[hairydog]

That is the perennial question isn't it? How you know for sure a fridge light really goes off when the door is shut

I'll tell you how I confirmed it: I set my phone to video and left in the fridge as I shut the door.

 

[wildebus]

Guess my question was a bit of a rhetorical one - bit like does a tree make a noise falling if no one in the forest to hear it (never understood that question though!)

 

[Wissel]

Don't know if anyone else has been waiting for these fridges to be back on Amazon, if so they are at £165

Inventor A++ Silver Mini Fridge, Internal Capacity 93L, Silent, Ideal for house, office and dormitories, Max Storage Capability, Energy Savings and Eco-Friendly: Amazon.co.uk: Large Appliances

Just ordered one myself

 

[wildebus]

They have come down in price as well! I paid £169.99 when I bought it!

BTW, If anyone is tempted by the other A++ MiniFridge that is 98L (this one - Inventor A++ Silver Under Counter Mini Fridge, Internal Capacity 98L, 4 Star Ice-Box, Silent, Ideal for house, office and dormitories, Max Storage Capability, Energy Savings and Eco-Friendly: Amazon.co.uk: Large Appliances ), note that although it is also A++ rating, it uses considerably more power due to the 4* Freezer Compartment.
The 93L has an icebox feature anyway and is good for keeping lollys frozen but not for long-term freezer use (who needs to keep food frozen for months in a campervan anyway?)


PS. If anyone fancies one of these Fridges and is up in the North-East or South East Scotland, I have a brand new one for sale which has a dented door right at the bottom (can't see it unless lie flat on the ground) and cracked plastic salad tray.
Bit of a long story but I ended up with two, so one is in my Camperbus and the other one is available at less than half new price.

 

[Wissel]

I installed the inverter and fridge this morning and have to say that so far I'm really happy with the setup.

I filled the fridge with bottled water to make it work hard to get down to temperature. No noise from the inverter at all and the fridge can't be heard from 2m away lying in bed. It's by far the quietest fridge I've ever used, house or van.

Hard to gauge power usage as only day 1 and its had a lot to cool, but I've used 380w since midnight (it's 9pm now, so 30Ah in 21 hours) to run my MaxxFan constantly, have my laptop on and plugged in from 7am, charge my phone and a couple of e-cig batteries, and cool the fridge from about 12 noon and have the inverter on from the same time (also with a 4G router plugged in).

As I know roughly what the other items use, I think the fridge/inverter combo has used about 12Ah in 9 hours, including cooling a full fridge from ambient. Very pleased with this, so thanks @Wildebus for this thread.

 

[wildebus]

Found something interesting in my Fridge+Inverter Setup which I thought worth sharing on this thread :idea-007:

I've been running the Victron Inverter in "ON" mode as it needs at least 15W to 'wake' it when in Eco Mode and on my testing I didn't think that the way the fridge started up would kick the inverter into life (there are some other non-fridge reasons why I left in ON, but will talk about them at the end).
I changed some communication wiring last night and now instead of using Bluetooth and an App to monitor/control the Inverter, I can use the Victron VRM Portal via the Raspberry Pi. To test that change, I decided to switch the fridge to ECO mode and have a play and that is how I discovered this new info :cool1:

So this graph shows how the power consumption changes between ON Mode and ECO Mode

On-vs-Eco by David, on Flickr

If you check out the power consumption between the peaks, in ON mode, it is around 22W and in ECO mode it is just 9W - so that is a difference of 13W* - or around 1Ah for 2/3rds of the time.
That equates to around a 16Ah saving over a 24 hour period. That 16Ah/Day* could be significant in some setups and even in my own with a decent sized battery and solar array it could be a useful saving over the wintertime

So my initial assumption that the ECO mode was not any use with a Compressor Fridge looks like it was not quite right :rolleyes2:


Now something that is specific to MY setup which means ECO is not actually the best setting necessarily are these:
I have an AC-Powered Network Router and Wi-Fi Booster. So when the Inverter goes off, the Network goes down! The Raspberry Pi actually automatically falls back to the built-in Wi-Fi linked to the Mi-Fi Dongle so that carries on communicating, but other devices (Laptop/Tablets/Amazon Echo/Fire TV/Now TV) will not.
(*note that the 13W saving from ON to ECO also includes the fact the Router and Wi-Fi Booster are no longer powered up either, so it is NOT a 13W Inverter Overhead).

I can see myself switching the inverter to ECO mode while the van is parked up not being used to minimize power use, and then switching to ON mode once I have setup camp so I can use the extra AC-powered facilities easily.


An curious aside is the visibility of the In-Rush Power Spikes now.
The Victron system is setup to sample/snapshot the data every minute. The in-Rush happens for just a couple of seconds each time the compressor kicks in, which is typically twice an hour. So only occasionally does the sample time co-incide with the in-rush event and so rarely appears on the graph.
Now I have connected the Inverter direct to the Pi **(running Victron GX software), the In-Rush seems to appear just about everytime the fridge starts up. It won't change the actual power consumed, but it might change the calculation of power used. (the Victron system might see a spike of say 300W and calculate that as being present for the full 1 minute sample period but it only lasts a few seconds).
**This spike 'visibility' could also be due to being in ECO mode as well? I am doing a test right now to check that and will update this part accordingly when I know

If this spike visibility IS much more common when in ECO mode, the Victron system could even report in the overview chart that I am using more power in ECO mode than I am in ON mode.
You know what they say .... Lies, Damn Lies and Statistics .....

 

[trevskoda]

Im looking at one of these rather than my 3 way which with a open flame burning in camper freaks my head out.

 

[wildebus]

Im looking at one of these rather than my 3 way which with a open flame burning in camper freaks my head out.

Trev, I would suggest THIS one instead ... Inventor A++ Compact & Mini Fridge,Silver, 45L Internal Capacity, Ideal for Bedrooms, Office and Dormitories, Energy Savings and Eco-Friendly: Amazon.co.uk: Large Appliances

Same brand as mine and same power usage, but the same size as the one you posted the picture of.
Currently bit more expensive then usual (they were around the £75 last time I looked) but - IMO - worth the extra over A+ models.

 

[Byronic]

I installed the inverter and fridge this morning and have to say that so far I'm really happy with the setup.

I filled the fridge with bottled water to make it work hard to get down to temperature. No noise from the inverter at all and the fridge can't be heard from 2m away lying in bed. It's by far the quietest fridge I've ever used, house or van.

Hard to gauge power usage as only day 1 and its had a lot to cool, but I've used 380w since midnight (it's 9pm now, so 30Ah in 21 hours) to run my MaxxFan constantly, have my laptop on and plugged in from 7am, charge my phone and a couple of e-cig batteries, and cool the fridge from about 12 noon and have the inverter on from the same time (also with a 4G router plugged in).

As I know roughly what the other items use, I think the fridge/inverter combo has used about 12Ah in 9 hours, including cooling a full fridge from ambient. Very pleased with this, so thanks @Wildebus for this thread.

12Ah in 9 hours that's a lorra battery power assuming constantinuous usage, conservative
est. 24Ah a day, unless a van is moved every 3 or 4 days a couple of average LB will under many
typical circumstances eg grey UK days be depleted, under a charging rate deficit.

Still there's nothing like an actual bit of in the field long term testing. I, as I expect
do others, would keenly await a report back based on those extended term findings.

I'm addressing this from a practical viewpoint. I fully realise that with unlimited
solar panel real estate and battery storage anything would be possible!

 

[wildebus]

12Ah in 9 hours that's a lorra battery power assuming constantinuous usage, conservative
est. 24Ah a day, unless a van is moved every 3 or 4 days a couple of average LB will under many
typical circumstances eg grey UK days be depleted, under a charging rate deficit.

Still there's nothing like an actual bit of in the field long term testing. I, as I expect
do others, would keenly await a report back based on those extended term findings.

I'm addressing this from a practical viewpoint. I fully realise that with unlimited
solar panel real estate and battery storage anything would be possible!

12Ah in 9 hours is a lot? ~150Wh? How much power (electric+gas) does your Fridge use? Compressor Fridges are pretty standard fitment in Campervans fitted with a small 100Ah battery.
I've have my AC Fridge powered up near-enough non-stop since October last year and I have so far had just two battery cycles recorded and my average SOC since April (the time from when I could record it) has been over 90%

 

[trevskoda]

Seen these in local adds ,asking £60 ono,no freeze box but im not fussed as i would buy fresh every day,just milk butter bread in fridge.

 

[wildebus]

Seen these in local adds ,asking £60 ono,no freeze box but im not fussed as i would buy fresh every day,just milk butter bread in fridge.

I would want to listen to them in operation first! those wine fridges are notoriously noisy (not important in a wine bar or pub of course, but middle of the night in a bedroom....?)

 

[Byronic]

12Ah in 9 hours is a lot? ~150Wh? How much power (electric+gas) does your Fridge use? Compressor Fridges are pretty standard fitment in Campervans fitted with a small 100Ah battery.
I've have my AC Fridge powered up near-enough non-stop since October last year and I have so far had just two battery cycles recorded and my average SOC since April (the time from when I could record it) has been over 90%

In motorhome terms, yes I consider 12Ah to be significant power use.
I self converted a brand new VW many years ago. I scrimped on nothing,
s/s everything to better the VW export Westfalias. I installed a compressor
fridge on the premise that the van was going to be used just for touring, moving
every few days, as indeed was intended with the factory Westfalias, utilising
as far as possible campsites with electric hookup. I had a leisure battery but
no solar (predated solar availability). I remember always being glad to get to a
campsite hookup if I had missed a night or so.
Now armed with that experience I make extrapolated assumptions on what
would have happened had I solar panels, sunny days, not so sunny etc.
My gas fridge consumes 240g of gas in 24hours even a CG 907 will give
10 days usage, no matter how much the sun shines or doesn't shine.
No electrical use other than a cupful of diesel via the alternator for the
12v supply on the move! Actually I don't even bother with that if the fridge
is packed with overnight cold contents and driving for up to a few hours.

I'm not saying reliance on battery and solar for a compressor fridge isn't
possible, or viable under certain restricted? usage regimes, but in the context of the
'average wildcamper', which is what primarily what this site
(presumably?) mainly represents, I just remain to be convinced that the compressor
fridge is the better option for the majority. I hope to be proven wrong!
I await real world (based on actual experiences) reports before I spend up!

 

[wildebus]

How much "real world" experience is required then?

3 years maybe? 5 years?


good to see you are using your "extrapolated assumptions" to trump actual installation information

 

[hairydog]

There are a few people who say that there is no problem running a compressor fridge without lookup, but I have noticed that every time I stop somewhere for a couple of nights that some motorhome or other has its engine running for a few hours each day.
Ask, and they all say it is to recharge batteries, and every one of them has a compressor fridge.
It seems that you need to have 200 or 300 watts of solar panel for the power problems to go away, and you can't park in the shade in hot weather.
On the other hand, loads of people have problems with gas fridges in hot weather: the venting and ducting isn't good enough to carry the heat away. Mostly adding vent fans fixes the problem, but it is a hassle and fridge burners and jets need cleaning every year or two. Few people have the confidence to do that themselves, and are (incorrectly) told that it can only be done by a Gas Safe LPG qualified engineer.

 

[Byronic]

How much "real world" experience is required then?

3 years maybe? 5 years?

good to see you are using your "extrapolated assumptions" to trump actual installation information

Yes 3 maybe 5 years (hopefully even more) as accumulated by a significant number of actual user feedbacks and reports.

I'm not asking anyone to take note of my experience that's just my own limited experience,
all I have to go on, just assumptions not certainties.
I await other peoples real world experiences however varied, before I come to any firm
decisions.