AC Fridge In Campervan -.Power Consumption Test

[wildebus]

Multiplus features?
Am I reading this correctly Dave?
2.3 Self consumption – solar energy storage systems When the Multi is used in a configuration in which it will feed back energy to the grid it is required to enable grid code compliance by selecting the grid code country setting with the VEConfigure tool. Once set, a password will be required to disable grid code compliance or change grid code related parameters.
If the local grid code is not supported by the Multi an external certified interface device should be used to connect the Multi to the grid.

Does this mean whilst I'm parked up at work, or home and connect to my building mains supply. I can use the normally wasted solar absorption of my Motorhomes solar array to offset my consumption of grid supplied power?

Now that would be a handy feature if it was so.

That (ESS) is a feature of the Multiplus IF is supported in your location. Think in the UK you can generally ignore that feature

 

[SquirrellCook]

That's a shame, just think how many motorhomes could top up the National grid.

 

[ScoTTyBEEE]

Bumping this thread in case anyone is waiting to buy the fridge in question as it's on offer today for £87.95

Inventor Mini Fridge 42L, Black, A++ Energy Savings, Ideal for Bedroom and small Office space.: Amazon.co.uk: Large Appliances

Buy Inventor Mini Fridge 42L, Black, A++ Energy Savings, Ideal for Bedroom and small Office space. at Amazon UK – every day low prices

www.amazon.co.uk

 

[wildebus]

Bumping this thread in case anyone is waiting to buy the fridge in question as it's on offer today for £87.95

Good Spot!
I have the 93L version
Inventor A++ Silver Mini Fridge, Internal Capacity 93L, Silent, Ideal for house, office and Campervans
and at under £90 it is a steal!
It would make a great fridge for the home as well.

Just bought another one as it is such a bargain ....
Order Number: 202-9772249-6245xxx
Inventor A++ Silver Mini Fridge, Internal Capacity 93L, Silent, Ideal for house, office and dormitories, Max Storage Capability, Energy Savings and Eco-Friendly will be delivered to xxx from Amazon EU Sàrl.
Delivery date: 24 Nov. 2019

 

[Duckato]

I have both sizes they use the same compressor and when bench the larger one was actually slightly more efficient.

 

[wildebus]

Holy Thread Revival, as they say!

Since I first started this thread, my ability to closely monitor the power use has significantly improved and I have I think got a good handle on what to expect in terms of power consumption of the fridge, and how long my Battery Bank could sustain my desire for ice cubes and cold drinks

The First Test was around March 2018 and I had 4 x 95Ah (@C20) AGM Batteries in a single bank of 380Ah (190Ah useable at 50% DoD)
Around May 2019 I replaced those batteries with 3 x 215Ah (@C20) AGM Lead-Carbon Batteries of 645Ah (387Ah usable at 60% DoD) - so a lot longer life there.

Today I have taken out the 3 AGM Lead-Carbon batteries and in its place there is a single Relion LiFePO4 Lithium Battery rated at 100Ah (100Ah usable at 100% DoD).
Started with a fully charged battery, and then turned off the mains, turned off the solar and disconnected the connection to the Starter so there is nothing that can charge the battery. Be interesting to see how long a mains compressor fridge, with the inverter overhead on top, will last using a single Lithium Battery
(PS. not going to try using the Induction Hob or Water Heater as those are too high a current load for a single 100Ah battery - even a Lithium one!)


Test started High Noon, 8th June How long will she (Lois the Lithium) last?

 

[SquirrellCook]

Holy Thread Revival, as they say!

Since I first started this thread, my ability to closely monitor the power use has significantly improved and I have I think got a good handle on what to expect in terms of power consumption of the fridge, and how long my Battery Bank could sustain my desire for ice cubes and cold drinks

The First Test was around March 2018 and I had 4 x 95Ah (@C20) AGM Batteries in a single bank of 380Ah (190Ah useable at 50% DoD)
Around May 2019 I replaced those batteries with 3 x 215 (@C20) AGM Lead-Carbon Batteries of 645Ah (387Ah usable at 60% DoD) - so a lot longer life there.

Today I have taken out the 3 AGM Lead-Carbon batteries and in its place there is a single Relion LiFePO4 Lithium Battery rated at 100Ah (100Ah usable at 100% DoD).
Started with a fully charged battery, and then turned off the mains, turned off the solar and disconnected the connection to the Starter so there is nothing that can charge the battery. Be interesting to see how long a mains compressor fridge, with the inverter overhead on top, will last using a single Lithium Battery
(PS. not going to try using the Induction Hob or Water Heater as those are two high a current load for a single 100Ah battery -even a Lithium one!)


Test started High Noon, 8th June How long will she (Lois the Lithium) last?

If the fridge was cold to start with up 48 hours, if not a little over 24. Place your bets folks. Winner get virtual dinner with Dave lol

 

[wildebus]

If the fridge was cold to start with up 48 hours, if not a little over 24. Place your bets folks. Winner get virtual dinner with Dave lol

I will send the winner the contents of the ice cube trays after the battery has discharged Will be via virtual drone, so just need to look to the skies

Good point on the fridge state. The fridge was fully cold (and actually at 0C) at the start of the test.
Not done the maths, but I am expecting around the 48 hours mark for the battery to go down to around 80% DoD (probably won't actually take it much past that it if I remember)

The prediction in the BMV (via the Victron VRM) is 28 hours (based on the last 2 hours of use). And those values are based on using 100% of battery capacity - so much lower than I would have expected. I think it is too soon for that be accurate, but we will see ....
(ust doing the maths on average power use so far that is recorded, there should be 38 hours?)

 

[Nabsim]

From what I have seen I think the true capacity of the RB100’s is 110amp or slightly more when new. You can maybe put me straight on that as tests go on Dave. Bet you nearly launched the Relion through the roof when picking it up after your carbon monsters ha ha

If it was my fridge alone running off that battery it would last I think approx 60 hours.

 

[wildebus]

From what I have seen I think the true capacity of the RB100’s is 110amp or slightly more when new. You can maybe put me straight on that as tests go on Dave. Bet you nearly launched the Relion through the roof when picking it up after your carbon monsters ha ha

If it was my fridge alone running off that battery it would last I think approx 60 hours.

would that be 60 hours without any charging at all? or 60 hours including solar?

 

[Nabsim]

60 hours with no charge sources connected

 

[wildebus]

Decided to modify my testing for this ...
I have too many external (to Fridge) factors to really be fully sure what the fridge is doing by itself, so at High Noon today, I will continue for another 24 hours, but with the Multiplus switched from "Inverter Only" to "Off".
This should tell me just what the Fridge and Inverter uses as that will be the difference in power between the two days. you can look at the logged data from the Victron system to see how much AC power is being used, but that doesn't cover the Inverter overhead aspect.
I have said about how the fridge has this large on-rush current spike for a couple of seconds when the compressor starts? Well, because of the way the devices are polled every minute for data, if it is polled just when that spike occurs, the logging system treats it as occuring for the entire minute so the current use is exaggerated in the download data (the BMV is always monitoring so its summary data does not suffer this issue, but it does mean using the logged data to make conclusions is a bit more tricky).

I do know I hit the 50% DoD (so the point where you would get concerned if you were running a Lead Acid Battery) at 22.5 hours into the running, which would suggest 45 hours is about the maximum - but bearing in mind there is more than just the Fridge + Inverter powered in the above time of course.

 

[Nabsim]

What’s using your power then Dave? I know at shows it would be higher but sat at home I thought you were fairly low. Your fridge doesn’t use anywhere near mine at 48 amps does it?

 

[SquirrellCook]

I do know I hit the 50% DoD (so the point where you would get concerned if you were running a Lead Acid Battery) at 22.5 hours into the running, which would suggest 45 hours is about the maximum - but bearing in mind there is more than just the Fridge + Inverter powered in the above time of course.

Are going to simulate opening the door too And if so for how long and many times? Just teasing as it looks like your testing is more involved than you hoped.

I'm still frustrated that my first attempt at running a domestic fridge worked so well. Under counter domestic fridge from Makro. About £100.00 Two 6 volt very used ex ups batteries about 200 ah new. Free! a 200W inverter of unknown origin. Very small can.
If the fridge door was not opened it would run for a week before the inverter screamed.
Early in it's second year of use the Inverter went Bang! one night. Very smelly.
A new inverter would not start the fridge.
Bigger inverter purchased.
Must be a duff fridge being hard to start.
Old fridge sold new fridge purchased.
New inverter wouldn't start it.
Bigger inverter purchased!
Batteries not lasting a day.
New Batteries purchased.
Batteries catch on fire and burn through plastic water pipe.
Fire contained and extinguished under the sink.

That's enough remembering that frustration.

 

[wildebus]

sounds enough to put you off cold food for life!!
My initial setup took a while to get right as the size of the inrush current was unexpected.
Victron 12/250 - wouldn't start it.
Victron 12/375 - wouldn't start it.
Victron 12/500 - starts (with a little thump each time). Ran for over a year 24/7
in the Victron range, the 12/1200 manages the inrush with no overload warnings, but the price hurts. The 500 could be borderline for starting with some fridges. the 800 is probably the sweetspot if budget won't run bigger (I am wary of cheap generic brand inverters that you want to run non-stop and mostly unattended for years).

 

[SquirrellCook]

the 800 is probably the sweetspot if budget won't run bigger

This is why I'm thinking the 1200 multipus should be a safe bet for the Betty build.

 

[wildebus]

What’s using your power then Dave? I know at shows it would be higher but sat at home I thought you were fairly low. Your fridge doesn’t use anywhere near mine at 48 amps does it?

48Amps? is that 48W for the fridge, or 48Ah/Day?

My power usage is not that much when in the driveway as not using the water heater or Hob - just the fridge as the key item. But ... I do have USB sockets active, the Victron Venus GX plus a Mifi Router always on; maybe the fan running (comes on and off by itself depending on temp).
Basically I don't want to have to think about any need for power conservation when got my "camping" hat on as opposed to "geek" propeller beenie on. The Solar has of course been off all the time as well, which would typically more than compensate for any power use for 4 or so months of the year and when parked up for around 9 months of the year

I've decided to extend the testing to do a bit of a comparison as well.
Day 1 - 100Ah LiFePO4 running supplying camper including Fridge (& Inverter)
Day 2 - Same battery doing same thing but without Fridge & Inverter
That will give some interesting info on how much the 230V Fridge comes into the picture.

The extension is this ...
Day 3 - 215Ah AGM PbC (Lead Carbon) Battery, setup same as Day 1 - camper stuff plus Fridge & Inverter
Day 4 - Same battery doing same as Day 4

My 215Ah AGM Battery could be a typical alternative to a 100Ah Lithium Battery (both around the 100Ah usable), so will be interesting how the two compare carrying out the identical tasks (using just one of the bank of three and currently doing a full charge to make sure we are starting from the same 100% stuffed full point for both batteries).

 

[Nabsim]

Over a 24 hour period my fridge will use 48 amps Dave, it’s the majority of my 65 amps per 24 hours usage.

I have a few illuminated switches always on, 12 volt turned on, fridge, water pump but most non 230v sockets not lit. I do have a 4way USB to cig socket that’s illuminated and always on and the broadband router is always on plus echo dot and BMV700 and Bluetooth dongle always powered up. Rest is used by lights and the 300W inverter when we watch tv, charge MacBooks or use the Sonos Play One. Both phones, watches and iPads are charged from the 4 way along with my bluetooth headphones.

I live in the van I don’t camp

 

[Nabsim]

Are you going to check out my theory that the RB100’s are actually 110ah and not the advertised 100? Some deals going round may be enough to push folks to spend that bit extra.

Just to add, my lithium is not Relion, they would have been my preferred make but costs were too much. I got a deal where I could get the TN-Power battery’s for £500 each delivered back end of last year and I couldn’t resist.

 

[st3v3]

On a slight tangent....

Did we talk about domestic fridges and needing to let them settle after travelling?

The instructions often say let sit for x hours before plugging in.

I have a hunch mine goes all screwy after a journey if it runs too soon after stopping or during driving.