Battery Problem, need help ASAP

Ian Paul

Free Member
Apr 24, 2018
45
13
I have just finished my conversion but volt meter gives a reading of 9v if I connect the dometic Fridge, is this normal ? please comment I have made a film to explain...
 

JJ

May 1, 2008
17,289
32,237
Quinta Majay, Pinheiro Bordalo, Portugal
MH
A Class
Exp
over 40 years
Are you running a compressor fridge?

If you have a "normal" gas/mains/12volt fridge, it does take a huge wack of electric on 12 volts... I think around 8 amps +...

I am not an expert by any means, but think the voltage drop is due to this considerable load being taken out of the battery...


JJ :cool:
 
Jan 19, 2014
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11,585
south shields
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Chausson 620 welcoome
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since 1990
Hi.. i suspect its telling you your battery has no capacity...
The voltage you are seeing is the solar panel voltage...
As soon as you load the system with the fridge which is most probably around 120 or more watts the load pulls the battery voltage down and a 100 w panel will not supply that sort of load..
Andy
 
Sep 18, 2016
285
491
Deep in the Lot
MH
Coachbuilt
Exp
2003-5, just re-purchased MH
Forgive me for mentioning it but starting three threads simultaneously on the same question can only lead to repetition and confusion...:)

As JJ says, if it's a standard 3-way fridge, running it on 12V from a battery doesn't work - the 12V operation is designed to be used from the vehicle alternator when the engine is running.
 
Jul 29, 2013
4,396
3,942
Salisbury
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Hymer B678DL A class
Exp
since 2011
Your solar is being used to run fridge but no enough capacity therefore draining your battery as well(y)
 
Jul 29, 2013
4,396
3,942
Salisbury
MH
Hymer B678DL A class
Exp
since 2011
As JJ says, if it's a standard 3-way fridge, running it on 12V from a battery doesn't work - the 12V operation is designed to be used from the vehicle alternator when the engine is running
We have our solar working the fridge but through the Schaudt control panel.(y) It will supply power when available.
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
17,990
16,911
On the coast in West Sussex
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Hymer B678 Dynamic Line
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Since 2008 & many years tugging
Either a duff battery or is there a problem with your wiring or solar regulator and the battery is not getting charged.

What happens it you charge the battery up on mains then with either the solar panels covered or disconected or in the dark. Does the same thing happen when you plug the fridge in? If so looks like the battery has had it.
 

TheBig1

LIFE MEMBER
Nov 27, 2011
11,150
13,669
Dorset
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A class
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many many years! since I was a kid
looks like your battery isnt charged, what you see before plugging in is the solar charging voltage. this is dragged straight down to actual battery voltage with the load applied
 

Cleve

LIFE MEMBER
Aug 27, 2015
772
2,290
France
MH
Hymer 654
Correct me if I am wrong (I am sure you will) but my understanding is that the 12v supply is from and when the engine is running and all that it does is to maintain the level as best it can that had previously been achieved while connected to the mains (EHU) or running off the gas.

My experience is that it is inefficient and will be struggling after a couple of hours. Though of course that could be just me.

If you have asked the question elsewhere I hope I am not repeating what others have said.
 
Oct 2, 2008
2,644
3,124
J10 M40
MH
Bucher Duro 6x6 motorhome
Exp
since 1968
@TheBig1 has pretty much hit the nail on the head , the solar (100w) cant supply enough to power the fridge , and the battery is flat (knackered) . What happens if you start your engine , if you have a good b2b charger set up . This should be enough to maintain a higher voltage in system .
 
Feb 9, 2008
5,255
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Corby, Northants
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Coach Built
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Since 2007
When you put a load on your battery, the reading will drop. It's virtually impossible to measure the battery state when a load is placed on it. The 14.4 V reading you have is a result of the power coming from your solar panel to your 125 AH leisure battery. The size of the load you are placing on the battery when you plug that 12V fridge socket is almost certainly the issue here. Can you work out how many amps it's pulling ? Finally, I would suggest disconnecting the power from the solar panel to your leisure battery and apply a small known load to the battery and see how it behaves. If it drops right down quickly it could be an indication of little to no capacity left in the battery and if so it may need replaced. (i would try and recover it first with a good quality battery charger). You don't say if it's Lead Acid, AGM or Gel. Gel can be heavily discharged without causing damage to the battery. If your battery is goosed and your going to replace it and you still want to run the fridge from your leisure batteries I would suggest getting more solar power (as much as you can) and possibly another leisure battery depending on the type you have. Remember to make sure your on board charger can cope with the extra capacity.
 
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