Going "3 way.." would be a "backward step.."    I have been through various "3way.." fridges - all had problems (in hot weather ,not cold when you need it , high current draw on 12 volt...plus needing gas ....) always dramas - glad to see the end of them. You will not look back if you get a good (most are ..) Compressor type.  KB

Just a quick one, we run ours on the minimum temperature setting "1", any lower will just goggle the gas!

Bass wrote:

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Well well well......Having eliminated reverse feed through the solar system, the solar was connected late yesterday and even though it was raining and cloudy the solar went straight to work, I then turned fridge on, it was draining the batteries at 4.3amps. At 7pm freezer was -15deg C , fridge was +4.5deg C. and 12.9v and 0 amp draw.... 7am this morn freezer +1.5deg C, fridge +14.8deg C RED light on fridge flashing and batteries 11.0v.
Fridge coming out and 3 way going in, THE END.
Thank all for suggestions and imput.

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 That is about 10% more than my 28L fridge uses when the compressor is running.

 

How many minute per hour is the compressor running?

I had enough of the system and decided to let it be and hopefully explode but of course that didn't happen. solar kicked in charged batteries and at some point fridge came on. lunch time was standing in van just looking at fridge and controller freezer was at -2.1 deg c and fridge +6.7 deg c and it was on but not going, controller reading 12.( something cannot remember ) and i'm thinking fridge should start up but it didn't, the controller was reading 0 amp draw then for a few seconds 0.3amp draw and repeat. So I decided to start the fridge manually by hitting the mode button and adjusting fridge tempt. fridge tried to start controller went below 11v and fridge went to fault mode.
Fridge should not of lost that much tempt over night and if seals are shot fridge should of started up but didnt...... fridge comes out.
Will have a look at inverter fridges etc though.

solar has been on and batteries indicate fully charged. fridge was off, 13v at controller, and 13v at fridge so no loss there, and 13v at battery terminals. freezer +5deg, fridge + 14deg. at 4pm turn fridge on it started no problem Trek controller indicated 5.3amp draw but that was moving about a bit. An inverter fridge from Hervey Norman will fit. see what happens back in oncology monday so will be a slow process now.

5.30pm... Freezer -11.9deg, fridge +6.1deg, trek controller indicating 0.3amp draw and voltage of 12.8v, and fridge on idle. Whilst i were there fridge tried to start, amps shot to 6.3amps and voltage dropped to 11.1v and fridge tripped to default red light blinking.

The top 9 rows show the starting voltage & the voltage just before the compressor turns off of my 28L fridge. Only a drop of 0.2 volts.

Starting & finishing amps. 4.6 down to 4.5 also 3.8 down to 3.7/3.8.

Using a 5 year old 80AH Exide starter battery.

 

(I spent 3 days in 35°C heat writing down data every second)

12.8 volts. Apply load of 6.3 amps. Voltage drops 1.7v to 11.1 volts.

I don't get that voltage drop when starting 3 ARB air compressors at 90 amps off 100AH battery.

 

I doubt the fridge needs over 100 amps, a fuse would blow.

Warren, are you attempting to run an absorption fridge on the batteries? If you are, then that is why you are having power problems. Three way fridges should never be run from the house batteries. They should only be run from the tugs battery whilst the motor is running. If you keep doing so, you are certain to destroy your batteries, no matter how large they are.

PeterD wrote:

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Warren, are you attempting to run an absorption fridge on the batteries? If you are, then that is why you are having power problems. Three way fridges should never be run from the house batteries. They should only be run from the tugs battery whilst the motor is running. If you keep doing so, you are certain to destroy your batteries, no matter how large they are.

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 He has a compressor fridge running off 2 x 120AH.

Fridge rated at 9.6 amps. So 6.3 amps would be about the correct typical amps while the compressor is running.

 

6.3 amps is not going to cause a 1.7v drop with 240AH of batteries.

I guess you could disconnect the fridge and wire it to another battery, not connected to the van to test it. Bit of stuffing around but would determine for certain if it's the fridge.

Whenarewethere wrote:

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Bass wrote:

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5.30pm... Freezer -11.9deg, fridge +6.1deg, trek controller indicating 0.3amp draw and voltage of 12.8v, and fridge on idle. Whilst i were there fridge tried to start, amps shot to 6.3amps and voltage dropped to 11.1v and fridge tripped to default red light blinking.

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Your problem is not the fridge.

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 I agree 2 batteries at 240Ah each, drawing 6.3A wouldn't drop the voltage enough to trip under voltage for days from fully charged, it should run 38 hours continuously  with the doors open just to bring the batteries down to 50% charge, without more testing the only conclusion I can arrive at is the batteries/wiring/connections are the issue, if the connections to the batteries are faulty then the charge and discharge might not be using both batteries or one battery bleeding into the other battery, or one/both batteries are stuffed. My thoughts are unfortunately stuffed batteries, only for the reason that with 460A of capacity and a short big enough that it drops your batteries to 10.5v as you said in the morning check your van would be ash or a fuse would have blown.

my suggestion is load test the batteries in the situation they are, disconnect everything except batteries then fully charge both batteries overnight then let them rest for an hour or 2 then measure the voltage of both batteries, use a measured constant load (inverter with hair dryer plugged in and on) or something similar, use a clamp meter to check out going amps from the battery bank also check the voltage at the battery as soon as the load starts, then repeat the same for each battery individually, this should give you some idea as to the condition of your batteries.

please note that AGM like all lead batteries usually have a discharge rating of 20 hours and if discharged at a higher rate the voltage drops a whole lot faster, so 480/20=24A/h and 240/20=12A/h in watts 480/20x12.6=  approx 300w and 240/20x12.6=150w, 12.6v being the nominal voltage of the batteries, drawing these amps the voltage drop should be minimal over an hour (maybe someone can work that out) given you have only used 5% of the storage capacity. if the voltage drop on the 2 batteries is excessive then do the test on them individually to see if one or both batteries have a similar drop.

To give you an idea of what this test should look like measure your tug battery voltage then turn the lights on high beam and measure again while they are on (don't forget to turn them off) this should give you an idea about typical voltage drop of a 12v battery, however the drop will not be the same as you will be pulling around 8.7A from a much smaller battery.

A for changing to a 3 way fridge the only 2 reasons to not use them is on battery they draw 15-20A constant and on gas they are not efficient and don,t work well in warmer climates, compressor has been around long enough that they just own and if yours only uses 6.3A for that size fridge I wouldn't be changing. I had an electrolux 220ltr in the 90's one of the best they said at the time and it used to use a 50kg bottle every 2 months, damn good 2 door fridge but gas was cheap back then $20 a 50kg bottle or as low as $14 in Melb.

I hope this isn's to much to follow or over the top, but if you can follow the testing then it should point out the problem. If it is your batteries give some thought to buying 2 100Ah lifepo4 instead, it will cost you a lot more short term but hey 12kg a battery and they will do exactly the same job, but you have to charge them different than lead, if you choose this path there are enough people here to explain all the lithium pro's, con's and how to change over.

Wanda you are right i have a power station, and old bloke I were thinking of doing that while walking the dog this morn, I have a 80ahr thumper with inbuilt 10.5v protection doing that would be easy. Peatop thankyou it did not dawn on me to plug in hair drier ( I have a 2000watt pure sine wave inverter already connected ). going to town this morn to get a clamp meter. The Batteries have been tested and I have to believe the battery bloke when he said the batteries are very good 2 x 260ahr new in 2020 ( maybe they have covid. ).
Where we stand at moment everything is connected up FRIDGE turned off at fridge and trek controller is reading 12.8v and has been 12.8v for over 12hours.
It has now become a quest. ( still putting my money on fridge ).

My four 26AH batteries have not been charged for about 3 weeks.

12.85v, 3 ARB air compressors 85amps, voltage drops to 11.35v just as tank reaches 145psi & compressors turn off.

 

A 6.3amp load can't drop battery voltage to 11.1v