Compressor Fridge.

oldbloke · Guru

RE: Compressor Fridge.

Whenarewethere · Guru

They are power wasters, but at worst about 20%.

If not using it turn it off.

If you are running a fridge off one get one to suit the capacity of the fridge to be more economical.

A second one for the kettle & induction cooker.

oldbloke · Guru

I knew there was something about dual batteries. Are the wired correctly. I believe just changing the red power cable can makes a difference. Someone with more know how might chime in on this. Pic indicates correct method.

https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/

Bass · Senior Member

NO. fridge is running off 12volt and for the sake of the test to eliminate the 12volt wiring to the fridge being at fault I plugged the fridge into the inverter. The van is in my driveway NOT connected to 240v.
Inverter is used for maybe toast in morning when free camping or when need 240v for some reason. otherwise it does not get used.
And yes the Batteries are connected as per your picture.

Whenarewethere · Guru

You are correct. If both cables go to the first battery there is resistance to the second battery so the first battery gets charged & discharged at a slightly higher rate.

peatop · Senior Member

Bass, just to quote you in a couple of posts, you said "Removed battery A and placed beside oven connected inverter plugged fridge in turned on 2 hours later still all good.????"

Do you have a voltage reading at the end of this test^^?

Then, "As I type the 100Ahr deepcycle battery is hard wired direct to fridge. starting voltage 12.9volts almost 5 hours later voltage is 12.47v."

I'm starting to think that it may not be your batteries at all but a fault in the wiring, I arrive at this because when you removed battery "A" and placed it by your oven, you then used alternative wiring to run the test, same as for the 100Ah battery ("C") is this correct?

Ok so lets look at your 240Ah batteries again, remove or not, But make sure you use the different wiring and test battery "B" (not the wiring in the van). It seems to me that somewhere within the installed 12v wiring loom for the van, there is either a fault or an unknown drain, If the batteries stay well withing the voltage range over 24 hours then you need to look at a wiring problem, however if the 240Ah batteries fail this doesn't mean solved as you then have to run the fridge on the 100Ah battery for 24 hours to then check the fridge, for this again fully charge the batteries so you get an accurate test.

If the fridge is at fault I would replace it with another compressor fridge, as others are saying I think you will be sorry if going to a 3 way hmm

iana · Guru

I'll Dometic converter.jpg

I'll try again. Our fridge is a Dometic RPD 217 compressor fridge. It is 12/24 volts dc, forget the 24volts, it is now only 12volts. The second picture shows the 12 volt connection. If the fridge is fitted with a converter as per last picture, and seen fitted to our fridge in the first picture, it will run on 240 volts independent of the caravan supply. The converter is a step down transformer and a rectifier, and a change over relay that switches over from the house supply of 12v to the 12v supply from the converter when 240 volts ac detected.

I have been trying to establish if you have this fitted, and I bet you have. This unit is added complication, and if the relay points are burnt will give a resistance to your system, You dont need this device, as you would have a 240 to 12v stepdown system in the van, presumably switching from house 12 to 240 v/12 if connected to the mains.

I have removed the converter, and in doing so have removed any resistance etc. in the circuit. Your fridge is only 12v.

oldbloke · Guru

"Ok so lets look at your 240Ah batteries again, remove or not, But make sure you use the different wiring and test battery "B" (not the wiring in the van). It seems to me that somewhere within the installed 12v wiring loom for the van, there is either a fault or an unknown drain, "

That's what I said a couple of days ago

Test fridge with each battery. Direct.

Could be a wiring short some where.

At this point apart from the freezer door looks like fridge is ok.

iana · Guru

Another thing that worries me, is how do you charge those two batteries, do you use a smart charger, what at say 30 amps, it takes quite a while to fully charge those batteries. Or do you use an old type of charger putting uncontrolled charge/voltage into them. If they are semi-sealed low maintenance batteries, there is a chance some of the electrolyte will have boiled off, if the charger is not the smart type.

I would, now knowing the circumstances, just go ahead and have a 200AH Lithium installed. The reason for this is when camping off the grid, being totally dependent on solar, your batteries will be low on charge come the morning, and you need to start harvesting the sun as soon as. Others know more about this than me, but I understand that lithium will except charge much easier than AGM batteries.

Your system should also be wired to take portable solar panels as well so that the panels can be set at an angle morning and at the end of the day.

oldbloke · Guru

I seriously doubt it's a charge issue. Poor charging might account for part of the discharge that is happening but not all.. His batteries are only lasting about 25% of what they should do. Something is drawing about 6 or 8 amps by the sounds of it. Needs to charge then run fridge off each battery on its own over night. Direct fridge. His old battery will do it.

If each battery holds up and fridge works OK then it's elsewhere. If 1 battery die then that's the problem.

-- Edited by oldbloke on Wednesday 6th of October 2021 10:35:07 PM

Gundog · Guru

Yeaterday at about 1715 we had a power outrage at the CP at approximatly 1800 I returned to the van and flipped the swith to have our Samsung Fridge run off the battery at that stage the battery was showing 13.1v with a small amount of solar input, by 1830 the battery was showing 12.7v no solar input, between 1930 and 2130 with the fridge and a couple of internal 12v lights the battery was at 12.4v. 2200 off to bed.

At 2330 power was restored I didnt bother to hit the change over switch, 0545 this morning no solar input yet but the Jayco Setec unit had been charging the battery and itb was back to 13.3v

Battery 120ah SLA which is 6 years old, Solar 75watt panel 5 years old, Fridge Samsung 228ltr Digital Inverter 240v Household Fridge.

Bass · Senior Member

Thats not funny Gundog.LOL.
iana no the back of my fridge does not look like that.
OK...old 100Ahr battery connected to fridge start voltage 13v at 1700hrs kept checking and have readings, at 0900 hrs battery 12.5v fridge still going. disconnected.
Everthing except solar connected up. 13.30 hrs battery voltage 13.45v. checked every hour and took readings. At 2200hrs battery voltage 12.82v measured at batteries 12.7v measured at fridge fuse point. Fridge trying to start but could not, starts / runs for about 5 seconds drawing 5.6 amps then trip, under voltage, battery volts dropped to 11v, measured at batteries. this continued for a few times each time current draw was 5 -6 amp range and battery would drop from 12.82v to 11.0v or 11.1v. each time. Turned off and went to bed.
Why did it run for over 8 hours no problem then decide buggar this and fault ?
Charging system now and will remove battery B and direct wire it to fridge and see what happens.
Tests started with fridge up to or rather down to tempture.

iana · Guru

OK that's it, I paste exactly what you have written as your make model of fridge on the net "etime.com.au/appliances/dometic-waeco-coolmatic-rpd-175dc-175litres-compressor-refrigerators-908.html" and up comes the pictures. It is obvious I can't help you.

kesa32 · Senior Member

Bass , maybe its time to get an auto electrician in mate , not trying to be smart , but stress is not good for your condition, maybe try and find a mobile one with a good reputation?

oldbloke · Guru

kesa32 wrote:
Bass , maybe its time to get an auto electrician in mate , not trying to be smart , but stress is not good for your condition, maybe try and find a mobile one with a good reputation?

Might be a good idea. But if I were bass I would want a couple of recommendations before seeing a sparky.

IMO it can only be:

1. The fridge

2. Faulty van wiring.

3. Batteries

If its 1 or 2 probably need a sparky or fridge mechanic

Bass · Senior Member

iana, yes mate that is what i have but the back doesn't look like that. it's close but i have a controller black box mounted on side of compressor that doesnt match yours. And Kesa32 yes mate I are going to when and if i'm allowed out of lockdown, the coppers have been patrolling this area a fair bit chasing melbourne people doing a runner to the murrey, and the auto elect said wait till after lockdown as he has no room a present.

iana · Guru

After a bit more searching on the net, I found a Utube video that shows a 240v lead coming down from the shelf where the compressor is mounted. I could not see where the wires went, but I am assuming it is basically the same thing but permanently mounted under the shelf. It is possible there is still a relay in there, switching between the 240v - 12v supply and the house battery supply.

Bass · Senior Member

Yep mate a relay would be in there somewhere, but its looking more like the batteries, charged both batteries and removed battery B and connected it direct to fridge at 11am. 12noon all good, 1300hrs all good, 1345hrs fridge on and trying to start but couldn't red light flashing. So dropped fridge down to eco mode to try and help it, no good. battery volts at terminals 12.8v. quickly got battery C ( old one 100ahr ) connected up and fridge started up straight away so switched it back off eco mode to where it was. Battery volts 12.6v and amp draw of 6.8amps, as I write fridge up to tempt battery volts 12.8v and 0.02 amp draw.
It is going to the auto elect but will be interesting to see if fridge runs till morning on the old battery.

iana · Guru

I think the fridge is fine, I'm putting my bets the batteries are the cause. Make sure the fridge is in the least coldest setting when running off the grid. There is a heater "climate control" quote:
"7.4 Heating cable
During the summer months of high temperatures and humidity, the metal frame
between the freezer and fresh food compartments may have water droplets
forming. This refrigerator comes standard with a 12V DC heating cable that will
evaporate the water droplets when they form.
To have the heating cable on,
you position the switch located
beneath the control panel to I,
see Fig. The heating cable can be
left on continuously or only used
when temperatures require it.
The heating cable will draw 12V DC power continuously when in the
ON (I) position. It should be turned off when a charging source is not
available." as written in the user manual. Good to see you're talking to me at last.

Bass · Senior Member

Sorry mate didn't realize I were rude, stressed out still not got all clear on cancer, locked down, and van playing games with me , sorry. ordered a crane to lift the batteries out of van and into the cruiser lol, going to get a draw down test done on both batteries. Battery C connected up direct to fridge again and see if it runs for 14 hours again. auto elec said when thats done take van to him.

iana · Guru

Nope you weren't rude, and yeah "stressed out still not got all clear on cancer, locked down, and van playing games with me" I would be too. I too have had fun and games with the fridge. So at the lowest temperature setting (I mean with the freezer at -9, not -20) , and climate control off, the fridge should be drawing about 7 amps. Maybe cycling on for 6 min, and off for 6 depending on conditions.
The next point is in our van we have a Setec unit that, when on 240v drops the voltage down to 12v dc and supplies the system which is all 12v, also charges the batteries. The fridge is wired into this via a 15amp fuse. Is your setup like this ?

-- Edited by iana on Thursday 7th of October 2021 08:01:13 PM

-- Edited by iana on Friday 8th of October 2021 12:20:49 AM

Whenarewethere · Guru

As has been mentioned.

I had an issue many years ago with cables. After the 6th cable I found one which actually worked. It got that bad.

You have to divide up every component into individual repeatable testable components or you will simply go around in circles.

peatop · Senior Member

As batteries go down hill the voltage often shows as normal but the amps are gone, once a load is connected the voltage drops proportional to the load depending on the capacity remaining in the battery, something like your car battery, when new it will crank the engine for a given period before it stops as the battery gets older it wont crank as long yet the starting voltage remains pretty much the same as when it was new.

This is what pointed me to your batteries being the issue in my first post, with a total of 480Ah and the voltage drop you have tells me that if you had a short it would have caused a fire to use that sort of power. so it meant the batteries needed to be tested.

Then running the fridge for 16 hours on the 100Ah battery and it only dropping 0.5 volts sounds to me that the fridge is fine. but what if you put the 100Ah battery where the 240Ah batteries fit and connect everything to it as normal and run the test again? although be aware that the 100Ah is a bit small for your output so keep the solar pumping just to keep from dropping the battery below that 50% SOC.

I read back to the original post in 2019 (read no, skimmed over it) what terry said was pretty much the same thing I've been thinking, whats been done since then to rectify the issues you had?

Also what others have been saying about cable size, believe it, if your cables are not big enough they are just resistive loads, and loads burn power.

Whenarewethere · Guru

Some really good points mentioned above.

Lead acid batteries will more than likely to still start the car but there is no reserve of AH.

My Land Rover is so stuffed full of electronics that it clearly shows up that a 4 years old battery is not worth the risk being remote.

Wire resistance. I pulled my fridge apart as I was loosing 0.17 voltage due to the under sized wiring within the fridge, let alone external cables.

0.17 volts may not sound like much. But a tiny problem here, there & everywhere adds up to a major issue.

Bass · Senior Member

Just an update....on friday morning dropped both big batteries off at battery place for a slow draw down test. home at 11am and just because I could I connected up the little 100ahr battery to the system and decided to let it go and see what happens. Well fridge still running this morning voltage at 12.7v was at 11.9v at 7am solar charges during day fridge draws at nite.

Aus-Kiwi · Guru

So what is the issue ? Fridge is still running ? As in working ? Is it cold enough ? Turning off ? Still working as in good due to high enough voltage ? Wire size is critical half a volt choke is enough to trip low voltage cut out if battery gets low ? Also make sure voltage regulator is set to CORRECT charging voltage ! Had issues with friends calcium batteries set too low . There wasnt much cycle between charged & flat or low volts !! I had similar issues some time back with FUSE . It was cracked created intermittent supply ! Pain to diagnose & find ! So simple to fix . All GOOD when WORKING ! Pain when things dont !

Wanda · Guru

Bass wrote:
Just an update....on friday morning dropped both big batteries off at battery place for a slow draw down test. home at 11am and just because I could I connected up the little 100ahr battery to the system and decided to let it go and see what happens. Well fridge still running this morning voltage at 12.7v was at 11.9v at 7am solar charges during day fridge draws at nite.

I would think 11.9v at 7am in the morning, running off only 1 x 100amp battery overnight, would be about normal. Voltage upto 12.7v with solar charging, again I would think sounds about it, although you did not say what time this was for solar to charge!!But again allowing for a couple of hrs of sunshine sounds about right.

Sounding more like a problem with either 1 or both of those other "huge" batteries.

Lets hope your on the path to sorting it, very very frustrating for you and you really don't need it with your health issues

Good luck

Ian

rgren2 · Guru

Is the temp battery in where the big batteries reside and using the same wiring?

Wanda · Guru

rgren2 wrote:
Is the temp battery in where the big batteries reside and using the same wiring?

Good point, it could sort the wiring issue if it was, I would think!

Ian

oldbloke · Guru

Wanda wrote:
rgren2 wrote:
Is the temp battery in where the big batteries reside and using the same wiring?
Good point, it could sort the wiring issue if it was, I would think!
Ian

Agree. If not bass shod probably do that.

Bass, did you fix t h e freezer door ok?