Leisure battery not charging from EHU or when driving

[John9894]

Hi, hope someone can help. I've got a Fiat Burstner Nexxo T660.

The leisure battery is not charging from electric hookup or when the vehicle is being driven. The panel shows no increased voltage when doing either. So the only charge the battery is receiving is coming from the solar panel on the roof.

Is this likely to be a fuse issue?

Thanks

 

[John9894]

Just to say when I turned the engine on, the panel showed the engine battery had increased it's voltage whereas leisure battery just stayed at 12V. The voltage on leisure battery only started to show an increase when the sun had come up.

 

[pappajohn]

Poor connection at the battery post/s or 50a master fuse, near leisure battery, has blown.

 

[John9894]

I've checked the fuse and no signs of damage on it. Probably worth buying a new one and trying it anyway? The connections all appear to be secure.

 

[John9894]

If this fuse has blown, would it not prevent the battery charging from solar?

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[autorouter]

If your MH has a split charge relay, then that requires two power connections (with a fuse on each), one from the alternator/starter battery and one from the leisure battery. The relay also requires a D+ signal from the alternator to trigger it.

The split charge relay will very likely be built into the distribution/fusebox, and these are all very similar but different in their details. What is the make/model of the distribution/fusebox in your MH?

Another question - what year is your MH? The latest ones have a smart alternator, and have a B2B charger instead of a split charge relay.

 

[John9894]

The split relay is Schaudt. The vehicle is 2011. The manual states it's an internal polyswitch (2a) for the D+ signal. Not sure how I'd check it it works because there doesn't appear to be a fuse, just a plug in.

 

[Jo662]

Hi ,I can’t help with your problem,but you will need to subscribe to be able to ask anymore questions. It will be the best £20 you will spend and open up a mine of info for your motorhome.

 

[GeoffnDee]

I would not expect the D+ to effect the EHU charging and you say this is not working either , I would double check the fuses and connections. The solar may be connected directly to the leisure battery , via a controller and its own fuse , so could still work ok.

 

[autorouter]

The AD01 is an interface between the vehicle electrics and the motorhome circuits. It might be of some importance later, but if you're not getting charge from the EHU it is not relevant.

It's a Schaudt unit. Schaudt also do Electroblock (EBL) distribution/fuseboxes, which usually contain the EHU charger, fuses and some relays including the split charge relay and the fridge relay. All these EBLs are similar but slightly different in detail, so it helps to know the EBL model number. Does your MH have an Electroblock, and if so what model is it?

However the first thing to check is the 50A Maxi fuse and 2A standard fuse near the leisure battery - the two in your first picture. Do you have a multimeter?

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[autorouter]

There's a fuse in the EBL, labelled 'Internes Lademodul', that is on the output of the built-in EHU charger. It's worth checking that (probably 20A). If you have a meter, you could check the voltage at the terminals of that fuse slot. One side should be the EHU charger voltage, the other side should be exactly the same voltage as the leisure battery voltage. It's a starting point for finding where the fault is.