AC Fridge In Campervan -.Power Consumption Test

[Nabsim]

We have a propane range style cooker at work and are still on the same 47kg cylinder for the last 8 years. When I lived in Wiltshire (no gas in village) a 47kg would last around 2 1/2 years at home. Murky was first fitted with a gas/mains caver water heater. It did seem to get through more gas than I would have liked. Hence the conversion to the calorifier. Though the down side of cooking with gas is the condensation

Cost of diesel hobs is a bit eye watering though huh lol
Will always be steam if you boil food though and how else would I get my bubble and squeak so I am okay with gas just for cooking

 

[SquirrellCook]

This is the ideal reaction of air and propane. A lot of water is produced. Even burning Hydrogen gives Heat + Water.
So Dave's mania for being all electric has it's plus sides if you can make enough electrickery.

 

[wildebus]

View attachment 2793
This is the ideal reaction of air and propane. A lot of water is produced. Even burning Hydrogen gives Heat + Water.
So Dave's mania for being all electric has it's plus sides if you can make enough electrickery.

mania! me!!

Actually, I was going to make a comment on the water by-product of gas .... my first flat had electric wall radiators which are a bit pricey to run so I bought one of those portable calor gas heaters to use instead in the sitting room. Produced so much moisture the plaster came off the walls! (or at least it contributed to that).

 

[xsilvergs]

@wildebus

Hopefully this gives some idea of fridge duty cycle, I would be interested to see equivalent for a 240V compressor fridge.

Image shows Leisure Battery volts from BMV, when volts are low inverter is running fridge, high inverter off. That's the best i can do at present I'm afraid, blame Victron. I can't remember what the sun/clouds were doing but I'm always disappointed by the amount of solar recovered.

Data from MPPT 100/30 with 400 Watts of solar. MPPT Charger State explanation 10 = Bulk, 7.5 = Absorption, 5 = Float

 

[wildebus]

Interesting.
To clarify, the fridge power cycle ... is the cycling due to the Fridge not demanding power all the time, or the inverter getting switched on and off as the battery SOC drops?

This is my info from yesterday ... I chose a time period that covers the solar kicking in so you can see how that changes the picture.
Top is the Solar; next is the AC Demand (via the Inverter) and last the DC Demand, 'polluted' after a few hours with the solar input coming in.

 

[xsilvergs]

@wildebus

From this image if we look at the time period between 11:30 to just after 14:00 the sun is strong enough to keep the battery over 89% so the inverter is enabled for this period. At about 90% SOC the MPPT charger would normally be in Absorption or Float mode but we can see it goes to Baulk mode about 3 times, this indicates to me that the inverter has kicked in to cool the fridge. The MPPT is delivering close to 20 Amps which means there is little drain on the battery.

There is probably 1 hour in this period where the inverter could be doing other things, heating water or running the Remoska etc.

Sometime after 15:00 until 18:00 the MPPT spends more time in Baulk mode and the SOC can be seen to rise and fall with inverter load. By this time the gas would be required to finish the duty cycle.

Perhaps I should log the "Solar Voltage" as this would give some indication of cloud cover.

The second graph up interestingly shows the Starter Battery and the Ablemail AMT doing its thing.

 

[wildebus]

I think you are right about the solar controller modes. I see the same thing when my fridge kicks on (Each inverter switch on is the fridge compressor spinning up)

I'll have to revisit this discussion in a few weeks I think when I can check out some stuff

 

[wildebus]

change of subject a little ....
I was working on configuring the Multiplus to work with Lithium and used the Fridge as a way to fool it into seeing a lower Battery Temp for testing purposes (sensor put into icebox in fridge). This exposed something quite intriging on the Inventor Fridge ...

This is what I usually record with the a Temp Sensor in the Fridge section of the Inventor Fridge. Typical pattern is the temp fluctuates very little (it is excellent in that respect in fact)

But today I put the battery sensor in the Icebox as I said (note that this is an identical sensor, but connected to the MP, not the Venus GX)
This is what the Icebox is doing when the Fridge is doing its normal power duty cycle

The Freezer seems to go down to -15C rapidly as soon as the compressor comes on, but as soon as it goes off, the temp goes up again nearly as fast. It actually looks like the Fridge Compressor duty cycle is linked to the freezer temp, kicking on when it is at OC, and off when down to about 15C?
Now the Info for the Fridge does say that the Icebox is not designed to be a freezer, but I would have expected much less of a range variation!
(PS. For info, in the chart above, the fridge is running on mains, not inverter)

Right now I can't do it, but next week I will put a sensor in Fridge AND in Icebox and map the pattern. Also today is a pretty hot day and that could have affected how it works somewhat.

 

[trevskoda]

Mine has been in van a week now and done two runs plus sitting in 34c inside van,works 100% on a nikkai smart soft start 600w inverter.

 

[wildebus]

Trev, have you actually monitored the temp over time?
Lots of people think their fridges work fine even when they turn them off overnight to save power but don't know they have warmed up and then recooled. Not good if you have meat products in there especially.

 

[Nabsim]

Mine only gets turned off when I defrost it

 

[trevskoda]

Trev, have you actually monitored the temp over time?
Lots of people think their fridges work fine even when they turn them off overnight to save power but don't know they have warmed up and then recooled. Not good if you have meat products in there especially.

Yes small t stat in fridge which is in the blue band about 2c 24/7,mine is never turned of and will run no bother all week on two 90ah batts and 200w solar,winter if i use van it may have to be plugged in at home before we go out.

 

[wildebus]

Yes small t stat in fridge which is in the blue band about 2c 24/7,mine is never turned of and will run no bother all week on two 90ah batts and 200w solar,winter if i use van it may have to be plugged in at home before we go out.

Did you see my point about how the fridge stays constant but the freezer/iceboxcompartment varies? have you checked both (if you have both)?

 

[Sprinter 1 cup]

See this fridge on currys site .
Https://www.currys.co.uk/gbuk/house...back~acknowledgement~product-details~05082020
Just a fridge no freezer but out of stock, Looks good but don't like handle ! What you all think

They will fit it for £35. Lol

 

[SquirrellCook]

Buy Beko UL584APS Under Counter Larder Fridge - Silver | Fridges | Argos

Buy Beko UL584APS Under Counter Larder Fridge - Silver at Argos. Thousands of products for same day delivery £3.95, or fast store collection.

www.argos.co.uk

This what I'm using in Murky.

 

[trevskoda]

Did you see my point about how the fridge stays constant but the freezer/iceboxcompartment varies? have you checked both (if you have both)?

No just looked at fridge,the we box is so small it will do for lollies only but i have not taken a reading as yet,will do so as ment to be -20

 

[xsilvergs]

I've had my eye on these:

https://www.ebay.co.uk/itm/DS18B20-Waterproof-Temperature-Sensor-for-Arduino-UK-Seller-/322461235769

for a future project.

Another job for the Pi

 

[wildebus]

I've had my eye on these:

https://www.ebay.co.uk/itm/DS18B20-Waterproof-Temperature-Sensor-for-Arduino-UK-Seller-/322461235769

for a future project.

Another job for the Pi

I just had a pair of these delivered actually ....

KeeYees 2 Pcs Temperature Controller Module with Case - XH-W1209 Red Digital Display Thermostat Cooling/Heating Module DC 12V with 30cm Waterproof -50~110℃ NTC Probe: Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop KeeYees 2 Pcs Temperature Controller Module with Case - XH-W1209 Red Digital Display Thermostat Cooling/Heating Module DC 12V with 30cm Waterproof -50~110℃ NTC Probe.

www.amazon.co.uk

Local control rather than Centralised Arduino/Pi, but for my requirement, need independant relay control

 

[xsilvergs]

I just had a pair of these delivered actually ....

KeeYees 2 Pcs Temperature Controller Module with Case - XH-W1209 Red Digital Display Thermostat Cooling/Heating Module DC 12V with 30cm Waterproof -50~110℃ NTC Probe: Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop KeeYees 2 Pcs Temperature Controller Module with Case - XH-W1209 Red Digital Display Thermostat Cooling/Heating Module DC 12V with 30cm Waterproof -50~110℃ NTC Probe.

www.amazon.co.uk

Local control rather than Centralised Arduino/Pi, but for my requirement, need independant relay control

They look neat and a good price too.
Is this for your van fridge?

 

[wildebus]

They look neat and a good price too.
Is this for your van fridge?

Charging control for Lithium Batteries.
They seem nice, but I do wish the relay had a NC as well as an NO - would make it much more flexible (for example, one device might need a 0V line to stop it but another might get activated by a 0V signal. If you had NC and NO, you can control both at the same time).

The units didn't come with any kind of manual, just a line on Amazon how to get a guide. So here is a link to get more info on the device - http://www.keeyees.com/a/Products/es/57.html

BTW, I don't know if you have a need for this kind of thing, or already have a preferred setup, but these 240V SSRs I have found very handy:

Amazon.co.uk

(when available, they were £15 for 3 including the heatsinks)
I have one on the water heater controlled by the BMV Relay for when it reaches a certain SOC.
Got another one in the shed on a battery box, controlled by another BMV and which activates when the SOC drops below a certain value - and turns on a battery charger so it doesn't go too low without getting a recharge but prevents having to have the charger on 24/7 or remember to use it manually.
I like these as they are high-power units (some of the multiway ones look like they couldn't handle too much power?)