# Electrolux fridge draining battery on 12v



## WhiskyRoller (Jan 30, 2010)

Hi,

We have a motorhome with an Electrolux RM6505 fridge. It automaticly selects Gas/240/12v. The fridge works absolutely fine but when I am on the road (12v selected), I find that my leisure batteries are draining. I have found if I leave the fridge off the batteries charge normally.

I am pretty sure that there is not problem with my charging system, so need to have a look at my fridge.

Has anyone had a similar problem or could point be where to look? My gut feeling is to have a look at the 12v element/wiring. Do you think I am on the right lines?

Thanks in advance


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## boringfrog (Sep 22, 2006)

Have you checked the fridge fuse?


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## WhiskyRoller (Jan 30, 2010)

Hi, Thanks for the suggestion.

The fuses are fine. The fridge does cool normally on12v. It just seems to be drawing too much current.


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## Sprinta (Sep 15, 2010)

I would have thought if the 12v cooling is working then the first point to check is how well it is charging. Perhaps the alternator isn't supplying enough for fridge and batteries together, but only enough to trickle charge the batteries


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## drcotts (Feb 23, 2006)

The other issue could be that a split charge relay is stuck. This is a relay that is energised when the ignition is on. When energised a 12v feed from the battery is closed to power the fridge. It should open again (disconnect the 12v feed) when the ignition is off.

If the relay was stuck then the 12v feed would be permenently supplied to the fridge.

Phill


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## WhiskyRoller (Jan 30, 2010)

Hi, thanks again for the input.

The split relay is working fine (only closing when the engine is running), I did swap it with another relay in case I had some resistance in the contacts. (The fridge only switches over when it senses the 12v i.e. when the engine is running)

As for the charging, this is a more feasible fault. I haven't looked in to it fully yet, but the output stays at about 14.5v with the engine running on tick-over with all my lights etc. on. The voltage only starts to drop when the fridge is on (even if I turn every else off). The fridge is rated at 175 watts which is a similar figure to having all my lights on.

I was just wondering if anyone else had a similar fault before I start ripping things apart. I think the first thing I am going to have to do is find an ammeter and see how much current the fridge is drawing, if this looks OK then I am going to have to look in to the charging side of things.... unless anyone else has any other ideas?

Cheers


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## raynipper (Aug 4, 2008)

Leave it on gas......!!!
I don't think I have run a fridge on 12v. for more than minutes to check it works in 30+ years.

Ray.


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## WhiskyRoller (Jan 30, 2010)

Thanks Ray,

I have a few issues with running on gas.

1) The fridge automaticly chooses 12v when the engine is running. (Although I could put the fuse to avoid this happening).

2) I hate things not working as they are supposed to.

3) I am far to tight to be forking out on gas when I can cool my beer for next to nothing when I am driving along!!


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## gaspode (May 9, 2005)

Interesting one, haven't come across this before. :? 

I think you need to first check the fridge current when on 12v, should be about 15a by the sound of it. Secondly I'd check the starter battery under load, it may have a high resistance in one cell causing it not to charge properly, then if all seems OK, get the alternator output checked.

A 15a current draw shouldn't overstretch the alternator, as you say it's no more than the road lights would consume. Do the headlights dim at all when you switch the fridge on with the engine ticking over?

I know it seems obvious but your alternator drive belt isn't loose is it?

PS: If you have a decent meter you could also check the 12v element resistance easily, shouldn't be much less than 1 ohm I wouldn't think.


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## philoaks (Sep 2, 2008)

As it can't cope with the fridge and leisure battery charging combined then it could possibly be some sort of resistive fault in the wiring/relay that is common to both.

One way to localise the problem would be to start the van and then (carefully) strap the leisure battery and vehicle battery together with a set of jump leads. If the fridge operates ok and the leisure battery holds at 14+ volts then that would point towards a wiring fault rather than a fridge fault. If the voltage starts to drop significantly then that would point towards an alternator issue. (IMO) 

Phil


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## WhiskyRoller (Jan 30, 2010)

Thanks gaspode,

Good point with the fan belt. I don't think this will be the case but it is always good to start with the simple things!

My 'van is lorry based (Isuzu) although a 12v system I have two large vehicle batteries (wired in parallel) & two one-year old leisure batteries.


Phil,

I think you could be on the right lines...

Bizarrely with the engine running and the fridge on I have noticed the Leisure batteries voltage reducing (around 12.5v) while the vehicle battery voltage seems to stay at around 14.5v. I don't understand this as the batteries are effectively joined together via the split relay. I do need to check the current drain when I get a suitable meter (mine will only check up to 10A). I will have to frig-up some leads to connect the batteries together as my leisure/vehicle batteries are some distance apart.

If this looks OK I am thinking along the lines of wiring and maybe earth's?????

Should prove interesting...... 8O


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## safariboy (May 1, 2005)

gaspode said:


> Interesting one, haven't come across this before. :?
> 
> I think you need to first check the fridge current when on 12v, should be about 15a by the sound of it. Secondly I'd check the starter battery under load, it may have a high resistance in one cell causing it not to charge properly, then if all seems OK, get the alternator output checked.
> 
> ...


12v and 100W aprox. should give something between 5 and 10 ohms.
Obscure problems like this often come down to earthing so a quick check might be helpful. A poor earth might cause the charging solenoid to trip out when the fridge trips in. It all depends on the exact wiring arrangement and is difficult to predict.


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## WhiskyRoller (Jan 30, 2010)

Thanks for the input,

It looks as if I am on the right lines (I hope)


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## gaspode (May 9, 2005)

> 12v and 100W aprox. should give something between 5 and 10 ohms.


It's a long time since I went to school but.............

V=IR

The wattage is stated as 175w and virtually all of this will be the resistive load of the heating element. At nominal 14v (when on charge) this should result in a current flow of around 12.5 amps.

I = 12.5
V = 14
therefore R should be V/I = 1.12 ohms

OK so we're talking approx values here - but 5 to 10 ohms??????


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## dalspa (Jul 1, 2008)

A simple check that you can do (if you haven't already done it) is to check the tightness of the 12v connections behind the fridge. Assuming you have two external vents, remove the bottom one. Gently tug at each of the thick 12v cables to see if they are tightly connected - usually a screw nipping the wires. Would be prudent then to undo and ensure bare wires are shiny and then re-tighten. Make sure that the fridge is switched off and engine not running when you do it - just in case.
We had a problem a few years back when running fridge on auto when travelling ending up with the 25amp(?) fridge fuse failing and the fuse holder melting. On checking the wires behind the fridge, they were all loose. Cleaned/tightened up and never had a problem since. Came to the conclusion that they had never been properly done up from new as I doubt that they would have all worked loose.

DavidL


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## safariboy (May 1, 2005)

gaspode said:


> > 12v and 100W aprox. should give something between 5 and 10 ohms.
> 
> 
> It's a long time since I went to school but.............
> ...


OK mine is about 100W and I was using 12V to allow for the voltage drop.


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## gaspode (May 9, 2005)

> OK mine is about 100W and I was using 12V to allow for the voltage drop.


Fair enough, but even so, to use your figures:

I = 100/12 = 8.3 amps
V = 12

R = 12/8.3 = 1.45 ohms.

Still not sure where you got the 5 to 10 from. :?


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## safariboy (May 1, 2005)

gaspode said:


> > OK mine is about 100W and I was using 12V to allow for the voltage drop.
> 
> 
> Fair enough, but even so, to use your figures:
> ...


You are quite right. For some reason I was calculating the current.


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