Caravan battery discharged by 12V fridge when travelling.

Submitted: Wednesday, Mar 12, 2008 at 22:18
ThreadID: 55493 Views:3612 Replies:7 FollowUps:16
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I have a caravan with a three way refrigerator model Electrolux
RM 2510.
The caravan has a battery which is charged by a solar panel, by a
240V recharger and by the car when travelling.
Everything was working OK until recently.
Now when I am travelling and the fridge is switched on 12V. the
battery gets discharged after 200 or 300 km.
When I turn the fridge off the car recherges the battery.
Can anyone give me an idea of what is wrong with miy battery/
fridge system and how to repair it
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Reply By: Member - Roachie (SA) - Wednesday, Mar 12, 2008 at 22:43

Wednesday, Mar 12, 2008 at 22:43
G'day champ,

What size cable do you have from your vehicle to the caravan battery?

My guess is that you are not putting enough charge into the c/van battery from the vehicle's alternator, to make up for the HEAVY draw that the 3 way fridge has on your battery.

I have an Ultimate Camper which come standard with a 3 way fridge (NB: I've ditched my 3 way fridge in favour of an Engel 80 litre upright, 2 way fridge cos the 3 way jobbies suck big time IMHO).

Anyway, the Ultimate people wire the vehicle up in such a way that the VEHICLE supplies the 12 volt power for the fridge, directly from the alternator (I think). That way, the on-board fridge is able to be charged during the day (also from the vehicle, but via a different cable). The downside is that if you pull-up somewhere for lunch or a bush walk etc, the fridge isn't getting any juice at all. The idea is that you would switch it over to gas if you were gunna be stopped for any length of time.

To me it was all too much hassle and the 12v/240v is much more practical.
AnswerID: 292437

Follow Up By: Shaker - Wednesday, Mar 12, 2008 at 22:45

Wednesday, Mar 12, 2008 at 22:45
"Everything was OK until recently"

So, I doubt if it is the cabling.
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FollowupID: 557818

Follow Up By: Member - Roachie (SA) - Wednesday, Mar 12, 2008 at 22:51

Wednesday, Mar 12, 2008 at 22:51
point taken,,,.....;-)
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Follow Up By: Dunco (NSW) - Wednesday, Mar 12, 2008 at 22:53

Wednesday, Mar 12, 2008 at 22:53
Battery must be cactus

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FollowupID: 557822

Reply By: Derek from Affordable Batteries & Radiators - Wednesday, Mar 12, 2008 at 23:01

Wednesday, Mar 12, 2008 at 23:01
You must check a number of things.

1) Have the battery load tested.
2) Check the connections (plugs, fuses, earths)
3) Test the relay or isolator for voltage drop or burnt / corroded contacts.
4) Check the alternator output.

Regards

Derek.
AnswerID: 292439

Reply By: Tenpounder - Wednesday, Mar 12, 2008 at 23:21

Wednesday, Mar 12, 2008 at 23:21
Hi there. Sounds familiar to me. I'd be suspicious of the 12V element in the fridge. Mine was blowing 15A fuses until I repaced the 12V element, then all was sweet.
AnswerID: 292441

Reply By: Faulic_McVitte - Thursday, Mar 13, 2008 at 07:55

Thursday, Mar 13, 2008 at 07:55
pay you to ask on one caravan forums where they have experience with that type of problem. People there dont guess and push you up the wrong tracks.
AnswerID: 292461

Follow Up By: Ircon - Thursday, Mar 13, 2008 at 08:59

Thursday, Mar 13, 2008 at 08:59
Most caravan wiring includes a diode to prevent the fridge being powered by the caravan battery.
Generally you power the fridge from Gas or 240 V when the car is not connected and only feed the fridge 12V when the car is connected from the cars alternator/battery or auxillery battery.
If it was working then maybe the diode is shorted. Don't know if that's likely or even possible.
If you have discharged the battery that much a couple of times the battery is probably damaged as well. Don't relace it until you get it sorted.

Regards,

Rosscoe
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Follow Up By: Member - Mike DID - Thursday, Mar 13, 2008 at 10:10

Thursday, Mar 13, 2008 at 10:10
People on the caravan forums also have the ability to remote measure voltage, current, resistance and temperature in your entire system, no matter where you are in Australia.

That way they don't have to guess this essential information and push you up the wrong tracks.
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Follow Up By: Mike Harding - Thursday, Mar 13, 2008 at 11:32

Thursday, Mar 13, 2008 at 11:32
>People there dont guess and push you up the wrong tracks.

In which case it must be the only forum of its kind across the whole of the internet.

Mengs: my guess is that the battery in reaching the end of its life. Ensure it's fully charged with your 240V charger and then ask a battery place to do a load test for you - usually a free of charge service.

Mike Harding
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Follow Up By: Nomadic Navara - Thursday, Mar 13, 2008 at 14:15

Thursday, Mar 13, 2008 at 14:15
Rosscoe

Caravans definitely do not have diodes fitted to prevent absorption fridges from discharging their house batteries (as a standard fitting.) Have you seen 20A or larger diodes? They press into a 1/2" hole in a large heat sink, the heat sink is necessary to keep them cool and needs to be mounted in free air where people will not place things that will restrict the air flow.

There is a device called a Fridgemate which is a motion sensing device that will switch off the power a few minutes after it stops rocking. These are available for after market fitting. However they take 15 minutes to switch off which allows considerable power drain after you have stopped. I prefer to wire my rigs with a separate wire to the fridge - this wire is controlled by the ignition switch of the tow vehicle so that when you kill the motor you kill the fridge too.

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Follow Up By: Nomadic Navara - Thursday, Mar 13, 2008 at 14:17

Thursday, Mar 13, 2008 at 14:17
MikeR

You can relax now and take your tongue out of the cheek ! ! ! !

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Follow Up By: Member - Mike DID - Thursday, Mar 13, 2008 at 15:11

Thursday, Mar 13, 2008 at 15:11
PeterD - are you implying I would post a non-serious msg before the FridayFunny ????
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Follow Up By: Nomadic Navara - Thursday, Mar 13, 2008 at 15:44

Thursday, Mar 13, 2008 at 15:44
MikeR

No I thought it was a serious post, just like the one you were answering.

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Follow Up By: Tenpounder - Thursday, Mar 13, 2008 at 15:56

Thursday, Mar 13, 2008 at 15:56
Gee, and I thought there really was a 'remote all things diagnosis' that was poised to remove all the guesswork! Actually, the magic machine must also detect intermittant dead shorts in the 12v element curcuit, possibly only evident in motion (as the element chatters around in its mounting).
My thinking (Guesswork??) is that, even if the charging circuit from the vehicle was open, the fridge should last a couple of hours at 12A before the battery is flat (2 or 3 hours = 24 to 36AH out of a storage battery), and the fact that the vehicle satisfactorily charges the battery when the fridge is off supports the idea that the problem is with the fridge.
Guesswork? no, just a large dose of 'been there', and a bit of logic.
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Reply By: Wizard1 - Thursday, Mar 13, 2008 at 12:52

Thursday, Mar 13, 2008 at 12:52
Sounds as though your charge rate isn't upto your usage rate.

SO which method of re-charge do you use when travelling, or is it all 3?

AnswerID: 292487

Reply By: Ken - Thursday, Mar 13, 2008 at 15:50

Thursday, Mar 13, 2008 at 15:50
Mengs, I understood that vans etc have 12v supply to the 3 way fridge only available when connected to the vehicle, ie the 12v for the fridge does not come from the van battery, for the very reason you are experiencing. The fridge will draw about 15 A on 12v.
What may have happened is the fridge supply was incorrectly [in my view] connected to the van battery and the battery may have handled it for a short time but after repeated heavy power drain it is now no longer capable of running the fridge and fails after a short time.
I have never seen or heard of an isolating diode in a van to separate the 12V supplies. Generally diode isolation is a recipe for undercharged batteries unless there is some means of compensating for the voltage drop across them.
Ken
AnswerID: 292511

Reply By: kiwicol - Friday, Mar 14, 2008 at 20:26

Friday, Mar 14, 2008 at 20:26
If you have a deep cycle battery in the van the alternator in the car will not charge the battery to 100%, so the more you use the battery the less it will be charged. By using the 240 charger it will charge to 100%, but not on a overnite charge if the battery has run down to a very low level. You would be better running a normal heavy duty start battery which the alternator will be able to charge fully on a normal days drive. have a look at the warranty on most deep cycle batteries and they will be signifantly less than a simaler priced starter battery, because under any application a car alternator will not fully charege a deep cycle battery, only a smart 240 charger will do that. col
AnswerID: 292718

Follow Up By: Dunaruna - Friday, Mar 14, 2008 at 20:36

Friday, Mar 14, 2008 at 20:36
- 'because under any application a car alternator will not fully charege a deep cycle battery, ONLY a smart 240 charger will do that. col' -

Only?
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Follow Up By: Nomadic Navara - Friday, Mar 14, 2008 at 20:54

Friday, Mar 14, 2008 at 20:54
Yes - an alternator will not fully charge a battery in a van, be it a starting battery or deep cycle one.

Regarding warranties on batteries - if they find out you have used a car battery as a deep cycle one the warranty is immediately reduced to zero. You can kill a car battery with as few as 20 cycles. They are not built for deep discharging - only deep cycle batteries are built for this type of duty.

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Follow Up By: kiwicol - Friday, Mar 14, 2008 at 21:46

Friday, Mar 14, 2008 at 21:46
never had any problems getting warranty on a car battery used for running a fridge as the questions i asked where answered by the battery supplier. I have always used ozzy made starting batteries x2 to run all the electrics in the GQ and C/T and nave been getting 2-3 years from a battery and thats using bore and town water to top up. The usage on the batterys is heavy as my trips have been anything from 6mths to a year living on 12 volts. Have met many people with the same problem this thread was written about, i gave my point of veiw to them and met them down the track and where more than happy with the advice i gave them as it solved the problems they where having, and they where bothe advised by the sales person of the van that deep cycle was the way to go and both got let down, Col
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Follow Up By: kiwicol - Friday, Mar 14, 2008 at 22:13

Friday, Mar 14, 2008 at 22:13
Dunaruna. Yes only. Col
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Follow Up By: Dunaruna - Saturday, Mar 15, 2008 at 00:09

Saturday, Mar 15, 2008 at 00:09
Did we forget solar?
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