Battery Problem, need help ASAP | MotorhomeFun | The Motorhome Support and Social Network

Battery Problem, need help ASAP

Ian Paul

Free Member
Apr 24, 2018
45
13
Funster No
53,560
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

Funster
May 1, 2008
17,886
37,228
Quinta Majay, Pinheiro Bordalo, Portugal
Funster No
2,459
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:

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Jan 19, 2014
4,140
12,699
south shields
Funster No
29,767
MH
Chausson 620 welcoome
Exp
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
670
1,610
Deep in the Lot
Funster No
45,188
MH
Autotrail Cheyenne
Exp
University of Life...
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.

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Jul 29, 2013
5,527
6,065
Salisbury
Funster No
27,215
MH
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
5,527
6,065
Salisbury
Funster No
27,215
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.

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Lenny HB

LIFE MEMBER
Oct 18, 2007
24,039
33,778
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
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
13,332
21,315
Dorset
Funster No
19,048
MH
A class
Exp
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
 
Sep 3, 2012
2,992
5,693
Cheshire
Funster No
22,759
MH
C Class Elddis 175
Exp
5+ years
Try plugging something in that takes less power than a fridge-if the voltage falls to the same then check your battery out

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Cleve

LIFE MEMBER
Aug 27, 2015
791
2,324
France
Funster No
37,938
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
3,604
5,431
J10 M40
Funster No
4,247
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
6,638
9,589
Corby, Northants
Funster No
1,455
MH
Coach Built
Exp
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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Lenny HB

LIFE MEMBER
Oct 18, 2007
24,039
33,778
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
@Jim, he has 3 threads running on this any chance of combing or deleting a couple, mighty confussing.

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hilldweller

LIFE MEMBER
Dec 5, 2008
33,126
36,116
Macclesfield
Funster No
5,089
MH
Zilch Mk1
Exp
From Aug 2007
You need a voltmeter across the battery in case there is a cable fault to your socket.
 
Feb 16, 2013
13,602
20,682
uttoxeter
Funster No
24,713
MH
ambulance conversion
Exp
50 years
is this a three way fridge, if so it shouldnt be used on 12 volt if the engine is not running

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Feb 16, 2013
13,602
20,682
uttoxeter
Funster No
24,713
MH
ambulance conversion
Exp
50 years
Jan 8, 2013
4,193
4,255
Dronfield - Derbyshire
Funster No
24,202
MH
Burstner Lyseo 690G
Exp
Happy FLT for 8 Years
I would suggest any battery that reads only 9v has lost a cell and is knackerd - no matter what it's connected to.
 
OP
Ian Paul

Ian Paul

Free Member
Apr 24, 2018
45
13
Funster No
53,560
Thanks for the replies, what size wire is recommended to use ? I have a new 125 amph leisure battery fro Halfords.

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Lenny HB

LIFE MEMBER
Oct 18, 2007
24,039
33,778
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
Can you have voltage only going into a battery. Are you winding me up again !
Possible if the regulator is duff or there is a wiring fault and the socket is only getting fed from the solar.

Would I wind you up Phil: Brilliant scheme you keep recommending what was it called, NCC Verified Battery Scheme.:rofl:
 
OP
Ian Paul

Ian Paul

Free Member
Apr 24, 2018
45
13
Funster No
53,560
AS an update I replaced the thin wire and replaced with 240v mains wire, with just the battery connected with 12.6v as shown on the control panel, and just connected the battery to the fridge it then went down to only 10.4v, all solar including its controller where not connected. I tried to see what would happen if the solar was re connected in fact the solar controller is completely dead, Ive only used it for 12 hours at most.

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