Battery drain

ederland

Free Member
Jun 13, 2014
2
0
Co Longford
Funster No
31,950
MH
C class
Exp
5
:cry:My starter battery is being drained by .4amps and it is the fridge that is doing the draining. Why does the fridge run off the starter battery ? Is this normal? why not the leisure battery? I have had to get a start from the ferry company the last 3 times .The fridge works perfect, is it a bad earth? I am confused, please help somebody. My van is a Lunar roadstar 780 built 2005.
 
Sep 3, 2012
3,595
8,888
Cheshire
Funster No
22,759
MH
C Class Elddis 175
Exp
8+ years
Hi
i don't think that a 0.4 volt drain will reduce your starter battery to such a point that it will not have enough amps to start the vehicle , unless that is the battery is not holding a charge anyway.I assume that the ferry starts your vehicle after the crossing -not before -if that's the case the fridge is not powered by the alternator because the engine is not running. The fridge would be off even though you have selected the 12 v for the fridge whilst you was motoring to the ferry.
I would have your cab battery checked.

best of luck:thumb:
 
Jun 8, 2012
1,611
1,668
Reading
Funster No
21,386
MH
Riot Van Conversion
Exp
Since 2012
:cry:My starter battery is being drained by .4amps and it is the fridge that is doing the draining. Why does the fridge run off the starter battery ? Is this normal? why not the leisure battery? I have had to get a start from the ferry company the last 3 times .The fridge works perfect, is it a bad earth? I am confused, please help somebody. My van is a Lunar roadstar 780 built 2005.

It is quite normal for fridge 12V to be off engine battery. This is because it is only used for ignition (negligible usage) or cooling (engine running only). I suspect, though, that the fridge is not the problem, but you are using one of those inaccurate current meters that don't have a proper zero. You probably just have a bad batt
ery. You'll need a multimeter and someone who knows how to use it to investigate further.

Subscribers  do not see these advertisements

 

sean n maggie

Free Member
Apr 29, 2014
673
328
leeds
Funster No
31,196
MH
autotrail
Exp
3
i always thought the fridge only run when the engine was running,,therefore it wont be on when you are on the ferry,,,,think you need a check on your main battery to see if its holding a charge and check your alternator is charging at the right rate too..
 

tonka

LIFE MEMBER
Jul 2, 2008
8,985
15,472
Cannock, Staffs
Funster No
3,141
MH
A class Burstner 800
Exp
Since 2000
Is it an Autotrail?? The system has a drain of .3 amps if you leave the psu switched on .
 
Last edited:

sean n maggie

Free Member
Apr 29, 2014
673
328
leeds
Funster No
31,196
MH
autotrail
Exp
3
Is it an Autotrail?? The system has a drain of .3 amps if you leave the psu switched on .

our psu turns off once i start the engine, only comes back on when i press power button and its an Autotrail...

Subscribers  do not see these advertisements

 

TheBig1

LIFE MEMBER
Nov 27, 2011
14,594
28,206
Dorset
Funster No
19,048
MH
A class
Exp
many many years! since I was a kid
standard 3 way fridge wiring utilises a relay to prevent the engine battery draining with the engine off. if the fridge is drawing a current on 12v with engine off, check the relay
 

Jaws

LIFE MEMBER
Sep 26, 2008
22,662
52,562
Thetford Norfolk
Funster No
4,189
MH
C class, Chieftain
Exp
since 2006 ( I think ! )
As the big 1 says..
The fridge should draw NOTHING when the engine is not running

if the fridge is drawing anything then the relay is stuck on


A bit of maths
All ball park figures but close enough

Lets presume you have a fairly large healthy cab battery that is a 100aH

Lets say once it gets below 20% capacity it will stand no chance of starting the engine
So you have 80aH to play with. ( unless you have a traction battery in which case you can go much lower.. say down to 10 % :Smile: )

At a .4 amp drain that battery will be down to below usability after just 8 days of the van sitting.

If you have an alarm fitted that will also be drawing current too.. So about a week and you aint going nowhere !
 

hilldweller

LIFE MEMBER
Dec 5, 2008
658
36,083
Macclesfield
Funster No
5,089
MH
Zilch Mk1
Exp
From Aug 2007
standard 3 way fridge wiring utilises a relay to prevent the engine battery draining with the engine off. if the fridge is drawing a current on 12v with engine off, check the relay

What about the interior light.

Subscribers  do not see these advertisements

 

pappajohn

LIFE MEMBER
Aug 26, 2007
39,290
35,550
Dark side of the moon
Funster No
172
Exp
Since 2005
if the fridge relay, with engine off, had jammed/welded closed you should see a drain of around 10amps from the starter battery.

thats why it only works with the engine running, otherwise the battery would be completely dead (as in destroyed) in around 8 to 10 hours
 
Top