ARB Fridge warming up. (2 Viewers)

[Tigerstripe40]

I have been working through a problem the last little while.
Here's the setup.
I have 165 watts of solar panel connected to:
Victron SmartSolar MPPT 100/20 charge controller.
I also have a Victron SmartBatterySense
This feeds a 110 ah flooded lead acid battery (Duracell brand, it's about 6 years old). SLI31MDC
The load goes through the Victron charge controller and I have 10 ga wire going to a blue sea fuse box that has 3 circuits connected.
1. ARB Fridge
2. Kenwood Amateur Radio
3. 12v auxiliary socket.

The amateur radio and the aux socket have the fuses removed.

Whats going on is that the fridge is in the truck all of the time and has been for 8 years.
I keep the fridge loaded with a 12 pack of la croix, a 1 gallon jug of water and several water bottles, so there should be sufficient thermal mass.
IT does get pretty hot outside, the last few days in SLC have been over 100 degrees.

Recently, the fridge will show a green light, showing that the compressor is running, but the temperature is not going down to the 25F (-4C) set point. It was hovering at 40F, and during the course of the day, the temperature climbed to 56F.

When I took these pics, it was about noon, 18C outside.

Whats interesting is that if I put the fridge on 120 VAC, the fridge will cool down to temperature really quickly.
I can then run it off the solar for 3-4 days before the temperature starts climbing again.

I am thinking it's either the battery or the charge controller setting.
Battery Preset is User Defined
Absorbtion Voltage is 14.4v
Flaot Volates is 13.8V
Equalization is 16.2v

Load Output is set for Battery Life.

All that said, I think the battery is getting tired.
I just don't want to shotgun a new battery at this if I don't need to, though I have wanted to upgrade the system to a 300ah LiFePO...

Any thoughts on my next steps here?

 

[e9999]

Your controller setting voltages look ok.
Was the fridge's compressor actually running (as in you can feel it, or hear it, not just trusting the LED) when the temperature inside was rising above the setpoint? Or was it off? If the former, there may be something wrong with the fridge or the temperature around it was truly ungodly high. (You may want to check the vents too, if those are plugged, it may not cool very well.) If the latter, is it possible that the battery voltage was too low for the fridge to run given its settings? You can easily tell the battery voltage at all times by looking at the Trends chart in the Victron software, and you should be able to see the voltage dipping when the compressor kicks in and v-v. You have the perfect data logging set up to make sure your battery voltage is fine. If the battery voltage never got into the lower 12Vs, it's probably not a battery issue. Or you could have a thermostat issue.
You can also check the power delivered by the solar system in the software, if you have 165W nominal, it should be possible to generate more than the power needed by the fridge (around 50W maybe?) during a good bit of the day if it's sunny and your panel is oriented properly.
What is this load output for?

 

[Tigerstripe40]

I looked at the trend overnight and as the sun went down, the battery voltage dropped off to 12.74v overnight and that is with no load on it (aside from whatever power the charge controller pulls when it's dark).

When I looked at the trend from noon-4pm there was a bit of current draw fluctuaion, .2 -> .3 amps. but the fridge could have been pulling 4 amps at that time to get the compressor to kick over and there was plenty of battery available.

For the solar trend over the time the solar was only putting out 2-3 watts, however this morning when the sun came up and the battery started charging, it was putting out 14 watts (no load on anything). Looking at the history, 2 days ago, it was outputting 120watts, but that was when daytime temp was over 100F and the inside of the truck was likely 120F

 

[John McVicker]

@Tigerstripe40 I had the same issues as you. Also keep my ARB fridge either in the 60 or 40 100% of the time. Here’s what worked for me to solve the problem. 1 hour of work & instant results.

Clean the coils of the fridge: I removed the fridge, took it slightly apart to make access to the coils. Throughly blew the area with the air compressor. Then took a damp rag & wiped everything down. Done!

EDIT: I’ve had this ARB fridge since either 2007 or 2008.

 

[e9999]

^ yep, the coils or the vents, same idea. But if either are plugged, it should not run better under AC than DC, though.

^^ you'd want to check the battery voltage under load, but 12.74V overnight with no load is excellent. That means a fully charged battery voltage at rest. (It is possible that the battery would have low capacity and show good voltage under no load, though, but not too likely I would think.)
If you meant 0.3A from the controller to the battery, that is very low. If the battery is fully charged and the fridge pulls 4A from it, the solar controller should compensate for that quickly and then provide the 4A in turn if there is enough insolation, so it keeps the battery charged. You should readily see that.
14W of power is not much. If that is when the fridge was not running, then it means that the battery is likely close to full. Or that there was little insolation if early in the morning.
If the compressor is running when the fridge temperature increases, then it is likely a fridge issue, not a battery issue. You should be able to tell from the data.
You'd want to try to correlate the voltage, power, and compressor run status and be very systematic to make sense of all this.

 

[Tigerstripe40]

@Tigerstripe40 I had the same issues as you. Also keep my ARB fridge either in the 60 or 40 100% of the time. Here’s what worked for me to solve the problem. 1 hour of work & instant results.

Clean the coils of the fridge: I removed the fridge, took it slightly apart to make access to the coils. Throughly blew the area with the air compressor. Then took a damp rag & wiped everything down. Done!

EDIT: I’ve had this ARB fridge since either 2007 or 2008.

I did that this afternoon, and blew out the dust on the coils. IT wasn't really that bad. The fridge sits in one of the insulated covers pretty much all of the time, but it was a great suggestion!

^^ you'd want to check the battery voltage under load, but 12.74V overnight with no load is excellent. That means a fully charged battery voltage at rest. (It is possible that the battery would have low capacity and show good voltage under no load, though, but not too likely I would think.)
If you meant 0.3A from the controller to the battery, that is very low. If the battery is fully charged and the fridge pulls 4A from it, the solar controller should compensate for that quickly and then provide the 4A in turn if there is enough insolation, so it keeps the battery charged. You should readily see that.
14W of power is not much. If that is when the fridge is not running, then it means that the battery is likely full. Or that there was little insolation if early in the morning.
If the compressor is running when the fridge temperature increases, then it is likely a fridge issue, not a battery issue. You should be able to tell from the data.
You'd want to try to correlate the voltage, power, and compressor run status and be very systematic to make sense of all this.

I'll plug it in tonight, after I Get it chilled down (Its loaded with a couple gallon water jugs right now, so if those come up to 80F it's no loss) and see what I Find out. Might take 2 weeks to reproduce the issue though.

 

[John McVicker]

I did that this afternoon, and blew out the dust on the coils. IT wasn't really that bad. The fridge sits in one of the insulated covers pretty much all of the time, but it was a great suggestion!



I'll plug it in tonight, after I Get it chilled down (Its loaded with a couple gallon water jugs right now, so if those come up to 80F it's no loss) and see what I Find out. Might take 2 weeks to reproduce the issue though.

Mine didn’t ‘look’ all that dirty when I went to clean it either. Evidently it doesn’t really take much dust/dirt to affect the cooling. Hopefully when you plug it in tonight it will show an improvement. Good luck.

 

[e9999]

^^ if the battery and fridge can be set physically close to each other, you could put the victron battery sense sensor in the fridge and it will record the temperature in there, together with the battery voltage etc so you can see better what is happening.

what is the low voltage cutoff setting on the fridge, and did the battery ever go below that?

 

[peesalot]

That happened to Luke Porter at Rubithon once, arb wouldnt cool on 12V, had to scrounge a 400w inverter. Cooling on 110v proves the comp, temp sensor, are working. Somewhere the 12v isnt, have you checked voltage at the plug at back of fridge ? The arb converts the 110 to 12 so its seems as though its a supply issue. Try using same system in truck to run a 400w inverter and see if the system will run fridge on that ?

 

[peesalot]

Stayner showed me something once to get an engel that wouldnt perform on 12v going once. In the cig lighter plug on the arb cord, take that tip apart, there is a little resistor or thingy ( not sure ) on the power wire, remove it, no idea what but it worked, fridge cooled on 12v without dumping the batt in 2 hrs. I have found voltage loss thats why I said test at fridge plug, I even opened up the fridge and checked the ohms on comp, voltage at various points , everything checked ok, was so frustrating to have a good fridge that I couldnt get to not kill a batt, then bill buys it for 200 bucks and shows me the trick, good deal for Bill and a lesson for me.

 

[Tigerstripe40]

^^ if the battery and fridge can be set physically close to each other, you could put the victron battery sense sensor in the fridge and it will record the temperature in there, together with the battery voltage etc so you can see better what is happening.

what is the low voltage cutoff setting on the fridge, and did the battery ever go below that?

I have the Fridge set to the Lo setting (11.1v restart) and the battery never gets below 12 volts.

Stayner showed me something once to get an engel that wouldnt perform on 12v going once. In the cig lighter plug on the arb cord, take that tip apart, there is a little resistor or thingy ( not sure ) on the power wire, remove it, no idea what but it worked, fridge cooled on 12v without dumping the batt in 2 hrs. I have found voltage loss thats why I said test at fridge plug, I even opened up the fridge and checked the ohms on comp, voltage at various points , everything checked ok, was so frustrating to have a good fridge that I couldnt get to not kill a batt, then bill buys it for 200 bucks and shows me the trick, good deal for Bill and a lesson for me.

There is no cig plug, I snipped that off, tinned the leads and it's going directly to my blue sea fuse block.
I'll check the 12v to the fridge when I get home.

I had the fridge down to 25F on 120v, and then put the fridge back on the 12v system last night.
It was 35F this morning, and I heard the compressor humming away.
Looking at the battery voltage it was pretty steady
Current draw was .2 - .3 amps all night.
I need to check it, and will do so in about an hour.

Thinking about it, I wonder if the blue sea fuse block isn't the issue.
I have my 2M mobile rig running through it and when I put it in high power mode (50 watts) and key up to transmit, the radio reboots itself.

 

[Tigerstripe40]

Here's the screenshots.from the battery and charge controller.

 

[peesalot]

The batt voltage has nothing to do with what the voltage is at accessory. The fridge transforms the 110 to 12v so it has to be something in the supply line, I think you have eliminated the battery as an issue. Forget all the equip. and hook the thing straight to batt and see

 

[Tigerstripe40]

I bypassed the fuse block (theres a big fuse on the battery and another on then fridge itself) and now the fridge is pulling the amperage I'd expect.

 

[TXSunDevil]

I would find a way to measure voltage at the unit. Sounds like a power issue to the fridge.

 

[Mrtwooooo]

I would be checking what voltage your fridge is seeing. I say that because I had my ARB fridge wired up pretty similar to yours. I had a blue sea 12v outlet wired to the load output on my Victron Smartsolar 75/15. Victron says the load output is rated for like 20 amps, so amps were not an issue. The main issue I was seeing on my ARB Zero fridge was the fridge was seeing a lower voltage that what the battery was at and also what the victron app was showing. I can't explain why it was seeing such a voltage drop but it was causing my fridge to go into its low voltage protection mode and shutting off.

When the engine was running the battery voltage was higher and the fridge voltage was still lower than the battery but not low enough to cause any faults.

I wired the fridge outlet back to the blue sea fuse panel instead of the load output on the Victron and didn't have the issue after that.

I do not know why the Victron MPPT was causing such a voltage drop even at a small load like a fridge.

Seems like you bypassed the victron and its working better.

My suggestion would be to get rid of the Victron SmartBatterySense and get the Victron Smart Shunt. The battery sense is just telling you the voltage and their shunt will show you voltage, amps/watts and give you a state of charge percentage based on the 110ah capacity ( or whatever you set it to)

 

[Tigerstripe40]

Seems like you bypassed the victron and its working better.

My suggestion would be to get rid of the Victron SmartBatterySense and get the Victron Smart Shunt. The battery sense is just telling you the voltage and their shunt will show you voltage, amps/watts and give you a state of charge percentage based on the 110ah capacity ( or whatever you set it to)

I did not bypass the victron, I just bypassed the fuse block. I wired the leads for the fridge to the feed lugs on the blue sea fuse block.

 

[e9999]

Looks like you have the fridge on the load output of the controller. It's good to have the voltage control there, usually, but it is also more likely to be a problem than connecting directly to the battery. If the fridge draws a lot of current on startup, the voltage at the fridge could be lower than what it needs and it could shut off. And you would likely not see that on the Victron app because it is a very short event. That issue could then be worse if you have the voltage drops on the fuse block, fuse etc, which could explain what you just saw.
Alternatively, it could also be that the disconnect voltage setting for the load output on the controller is set too high, and it would similarly shut off the output on startup.