Leisure batteries not charging from running engine

[Dogsense]

Advice Please.
Autotrail Delaware with Sterling power controller, charging mode - Smart, Solar Carging mode - Smart,
have two leisure batteries that charged from the Solar panels but not charging when engine running (van battery charged from running ‍ engin & Solar),
Any idea what can be the problem/fault?

 

[Robert Clark]

Check the fuse between the engine battery and the split charge relay

 

[PeteH]

Assuming your Chassis Battery is charging? (no red light on the dash?). The issue will likely be in the "smart charger". But as the previous poster said, check there is not a blown fuse first. Somewhere there will be a diode, (acts like an electrical one way valve) to stop the reverse current between the 2 "banks" of batteries, they have a tendency to fail.

 

[Dogsense]

Thanks. Sad to say but I don’t really know where to look.
Attached pics of my van battery. Help

 

[icantremember]

I'm no electrical wizard but is there a failed split charge relay? If you can find it just swap it with a similar relay to test.

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[Dogsense]

Wish I knew where to look lol.

 

[Ivory55]

Wish I knew where to look lol.

The black art of the 12 volt. Anything to do with motorhomes they always seem to hide stuff where a non mechanical normal person has no idea where to look.

 

[Dogsense]

The black art of the 12 volt. Anything to do with motorhomes they always seem to hide stuff where a non mechanical normal person has no idea where to look.

Thanks, now I feel that I am not the worst idiot lol.
But need help to find the hidden stuff.

 

[Ivory55]

Thanks, now I feel that I am not the worst idiot lol.
But need help to find the hidden stuff.

You’re far from alone.

 

[DavidG58]

Does the fridge switch to battery when engine running, presuming you have an AES fridge?

Our D+ relay failed that apparently tells everything that the engine is running and alternator has correct output

I now know where mine is but wouldn’t have had a clue where to look, but if the fridge is working when engine running you can rule out this relay

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[Feltwell]

If you've really not got a clue and can't find an obvious fuse you may be better off getting someone else to take a look - I suggest a short break in North Wales and whilst there get A and A Caravan Services to take a look, they are the experts in all things motorhome & battery related and very helpful I've found.

http://www.aandncaravanservices.co.uk/

 

[jockaneezer]

Have a look next to your leisure batteries, there's likely a jumbo fuse and a standard auto fuse in the vicinity. I had the jumbo fuse go on mine (never did find the cause, and after a check over, a replacement fuse sorted everything)

 

[Tea Bag]

(never did find the cause, and after a check over, a replacement fuse sorted everything)

Hi.
"Snap"
Tea Bag

 

[ChrisL]

There should be a fuse between the starter battery positive terminal and the split charge relay and also one between the split charge relay and the leisure battery close to the battery. Check out the link to see wiring diagrams for common split charge systems.

https://www.12voltplanet.co.uk/split-charging.html

 

[Dogsense]

Fridge working on 12v when engine running. Does it mean that the engin also Charging the leisure batteries?

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[Dogsense]

Thank you Chris, still can’t find the Split Charge Relay.

 

[Ivory55]

It would not be something simple like the batteries are so low that they need charging with stand alone charger first. No laughing I am no mechanic. Haha

 

[ChrisL]

I would try starting at the positive terminal of the starter battery and follow the leads from there, of the thicker leads the thickest one should go to the starter solenoid another should go to the alternator and another should go to the split charge relay.

 

[Wagoneer]

Most 12v systems these days (say, in the last 10 years) have the split charge relay to the hab battery mounted within the 12v distribution box. Usually mounted on the PCB (printed circuit board).

I assume the OP has measured the voltage on the hab batteries whilst the engine is running. The voltage should read anywhere between 13.5 and 14.4 volts.