Smart alternator and leisure battery charging

[Radorik]

I have a Victron smart DC-DC charger for a 100ah Pb leisure battery under the drivers seat with a few sockets and a diesel heater. This was fitted by a 3rd party.

Posted another thread but basically the alternator on my T6 T32 4motion DSG has failed. Just occurred to me that the morning on the day of the failure the leisure battery was completely flat as my Dometic 3-way fridge was left plugged in overnight (not very efficient on electric but can take gas bottles). Hasn't been a problem in the past as used to charge up again on a long drive.

Is it possible the alternator can be overloaded by the Victron trying to charge the battery? May be I've just got away with it before?

I've never played with the Victron settings; Checked and was in smart alternator, charger mode.

 

[oldiebut goodie]

A 3-way fridge should only be able to be operated on 12v whilst in motion - usually by using an ignition switched relay. It should not be wired to operate from the battery. They draw in the region of 12 amps constantly hence this means of operation. They are nowhere near as efficient as the compressor types.

 

[Salty Spuds]

I have a Victron smart DC-DC charger for a 100ah Pb leisure battery under the drivers seat with a few sockets and a diesel heater. This was fitted by a 3rd party.

Posted another thread but basically the alternator on my T6 T32 4motion DSG has failed. Just occurred to me that the morning on the day of the failure the leisure battery was completely flat as my Dometic 3-way fridge was left plugged in overnight (not very efficient on electric but can take gas bottles). Hasn't been a problem in the past as used to charge up again on a long drive.

Is it possible the alternator can be overloaded by the Victron trying to charge the battery? May be I've just got away with it before?

I've never played with the Victron settings; Checked and was in smart alternator, charger mode.

There’s no way can your alternator be overloaded by a correctly functioning Orion. The Orion will be pulling around 30A at full chat, the alternator will be capable of delivering over 100A depending on model.

 

[Radorik]

That’s reassuring thank you, I do normally unplug the fridge when not moving but occasionally forget and it completely drains the battery overnight. Until now it has always recharged ok. Just like it for the gas option when I’m at a campsite without hookup.

 

[roadtripper]

That’s reassuring thank you, I do normally unplug the fridge when not moving but occasionally forget and it completely drains the battery overnight. Until now it has always recharged ok. Just like it for the gas option when I’m at a campsite without hookup.

If it has completely drained the battery then it has wrecked the battery. A lead acid should never be taken below 50% as below this permanent and irreversible damage happens to the plates

3 way fridges are great but they really should never be used on the 12v supply. Any well managed fridge should cope with a couple of hours not being actively cooled, those few hours will put a heck of a load on even a running electrical system for very minor gain.

 

[Radorik]

Ok I’ve not done too well here.. I had the fridge as going across Europe I would be travelling average 8 hours a day, when stopping taking it out and either plugging in or gas. Won’t be doing that again.

 

[oldiebut goodie]

When I had a 3 way fridge I never used 12v, I travelled everywhere with it on gas only turning it off for fuel stations.

 

[rod_vw]

I would agree with most of the above relating to a three way fridge. However there should be no problem running it on 12v IF it is wired correctly. The 12v supply to the fridge should be controlled by an ignition operated relay that only supplies 12v to the fridge when the ignition is on.
Whilst folks frown on using the gas when on the move it is usually quite OK except at fuel stations or on Le Shuttle, sometimes the gas will blow out due to unusual gusts either from bad weather or passing HGVs. There should be no gas escaping in those situations as there is a flame failure device on the fridge burner that shuts off the gas supply if the flame goes out.
It's possible that when the Victron system was fitted it replaced an old fashioned split charge relay, that operating circuit is the same as the normal ignition controlled relay for the fridge. All of that could have been removed during Victron Orion installation and the fridge circuit made continuous, that should not have happened!

When you have the fridge working checked and if necessary corrected you will be quite OK to travel for long trips using the 12v setting reverting to gas or 240v EHU when parked over night etc. Some fridges are designed to switch over and ignite the gas automatically dependent on settings.

 

[TonyM]

I suspect the OP may be talking about a Dometic Combicool ACX3 30 camping fridge rather than the more traditional built-in unit. Maybe @Radorik would confirm.

I do agree that unless faulty, it is unlikely that a T6 alternator would be damaged by a Victron Orion.

 

[Radorik]

Yes it is a combicool with a 12v plug, mains plug and gas bottles, my van is a kombi and I had a leisure battery fitted for that and a webasto night heater. The 3rd party fitted the victron gear, webasto and a few 12v sockets.

Hadn’t considered running on gas during the trip as gets pretty hot/open flame, and wasn’t sure on the carbon monoxide. May be yours exhaust outside?

 

[rod_vw]

Sorry, I didn't think of that type of fridge, @Radorik NO you shouldn't run that gas fridge without being able to have the exhaust outside!

For your use I would advise a compressor fridge of some type.

 

[Radorik]

Yes thanks I’ll look into those fridges as an in/out job, only had a 2-way fridge in my old t4 westy which had a meths burner, didn’t realise you could get 3-way fitted ones. Couldn’t support two vans (and seams were going rusty) so went to the kombi. Cheers.