Hillside Birchover
- Thread starter Grainfoot
- Start date
I noticed some strange behaviour of the lights in the rear of the van running a CTEK charger of the van 240v sockets to charge the starter battery. I now top up the starter battery with the 240v supply switched off to the van.
Same here, I now disconnect the EHU lead, run it to the front and plug the Noco in with an adapter socket.
Is this with a split charge relay or a DC-DC converter? Trying to visualise what might be happpening.
That’s interesting, you’ve inadvertently answered a question as to why Hillside splice into the engine run signal and feed it back to the rear cupboard wiring. I now know what the relays in there do!
However, as far as I understand the VW split charge relay should only energise on the engine run signal, so the two batteries should remain isolated. Odd.
This sounds a very odd setup & I’m struggling to understand the rationale behind it tbh.
I did some investigation with mine this morning (2023) and worked out what is going on.
The 12V “engine run” signal (black wire) that feeds the VW split charge relay does not work quite as I expected it to.
When you connect a charger to the starter battery, the increased voltage wakes up the van and the “engine run” signal goes from 0V to 12V regardless of whether the engine is running. The signal remains high until the van decides to go back to sleep.
This has consequences.
I first connected up my EHU, put my Victron mains leisure battery charger (my replacement for the CBE 516) into PSU mode and turned on the lights (I have no leisure battery fitted at present).
Worked fine.
I then ran my NOCO 5A battery charger from the van 230V socket to my quick connect starter battery connector and turned it on.
The lights went out as the vehicle woke up and also just as unexpectedly my REDARC DC-DC also turned on to charge the non existent leisure battery because it is wired, as per its installation instructions, to the “engine run” signal.
Now on my install, I have separately fused the “engine run” signal so I can easily disconnect the signal feed to either/both the original Hillside wiring and / or the REDARC.
Disconnecting the “engine run” feed to the Hillside wiring and the lights no longer switch off whilst charging the starter battery with the EHU connected up due to the undocumented Hillside relay no longer energising. This stops the weird behaviour with respect to the lights and I think I will leave it disconnected as it was odd/disconcerting. I assume they’ve done it to protect the lights from the high alternator voltage when the engine is actually running, but I’m only hypothesising and as I’m going to be running a DC-DC the voltage will be more stable, so not an issue for me.
With regard to the ”engine run” signal starting the REDARC when charging the starter battery, I’m going to investigate further as to what the effect will actually be when I have a leisure battery installed.
With the original VW split charge relay, it means when you charge the starter battery, the increased voltage will wake up the van, turn on the “engine run” signal and the VW split charge relay will energise and connect the leisure battery to the starter battery so the charger will charge both until the “engine run” signal goes low again when the charge voltage drops low enough.
Yes, looks like VW just assume that a higher than normal battery voltage means the alternator is running and therefore the engine.
They could have used a bit more logic and ANDed it with an ignition on voltage so that a charger on the starter battery alone wouldn’t activate the “engine run” signal.
When I had the problem I was looking at recirculating earth currents with having the 240v ac applied to the van. It was only when the lights came back on as the volts dropped I got an idea what's was happening. It was confirmed by the dashcamera running off the map light USB switching on and off with the stop start of the engine. You would have though VW could have managed it better than just the voltage level being sensed?
@EAN Thanks for posting that, electrickery is not my strong point, but it seems to make sense, and explains why I had the issues with the lights seeming to be dead, and mild panic ensuing.
I've been plugging the van EHU in to the mains to charge the LB, then running the lead to the front to charge the SB. Next time I'll charge the SB with the Noco first and see what happens to the LB. It might save me having to top them up individually.
Obviously on sites, I'll be using EHU as standard.
I've been plugging the van EHU in to the mains to charge the LB, then running the lead to the front to charge the SB. Next time I'll charge the SB with the Noco first and see what happens to the LB. It might save me having to top them up individually.
Obviously on sites, I'll be using EHU as standard.
Given all the other complexities VW have built in to the T6.1 model, the engine run (alternator charging) signal seems very crude. It did make me wonder whether the presence of this ‘signal’ voltage will ensure the correct operation of the CTEK DC-DC / MPPT charger I’m planning to fit and the devices powered from the leisure battery. That said, from what I’ve gathered from your reports, there probably won’t be any problems.
As I write, I’m currently running a CTEK MXS 5.0 charger that’s hooked up to the starter battery under the bonnet, that’s in turn powered from the 13A socket installed inside the van, which is powered via the EHU. The display on the CTEK charger is presently showing it’s in the float phase (on the AGM setting) at 13.6V. The Hillside-installed CBE CB516 is concurrently charging the leisure battery.
That's what I did (although with a Noco rather than CTEK) the first time I charged at home. It shut off all the habitation area lights and pump though, so I've been charging separately.
It seems that this is normal though, so hopefully not an issue.
I’ve looked into this “quirk“ of Hillside disabling the habitation circuits when the engine is running to understand why; or in our case when the van thinks the engine is running:
It seems it’s a widespread practice across British Motorhome manufacturers. There’s no legal requirement to do so, but it means that they don’t need to carry out EMC conformance testing on the habitation installation to ensure it doesn’t interfere with the vehicle electronics, which would be a significant cost and required if, as a manufacturer they left them on.
www.conformance.co.uk
From my perspective, if camping off grid, then it would be beneficial to be able to just run the engine to put some charge back in the leisure battery whilst still being able to use the habitation area; so I’m not going to reinstate the “engine run” signal to Hillside’s wiring and will leave the fuse out permanently.
i doubt very many self builds add in relays or other circuitry to disable the habitation circuits when the engine is running.
It seems it’s a widespread practice across British Motorhome manufacturers. There’s no legal requirement to do so, but it means that they don’t need to carry out EMC conformance testing on the habitation installation to ensure it doesn’t interfere with the vehicle electronics, which would be a significant cost and required if, as a manufacturer they left them on.
Automotive Electromagnetic Compatibility Directive EU Information and Advice - Conformance.co.uk
Download the Automotive Electromagnetic Compatibility Directive. For Europe, European, EU. Latest developments for compliance with the Automotive Electromagnetic Compatibility Directive.
www.conformance.co.uk
From my perspective, if camping off grid, then it would be beneficial to be able to just run the engine to put some charge back in the leisure battery whilst still being able to use the habitation area; so I’m not going to reinstate the “engine run” signal to Hillside’s wiring and will leave the fuse out permanently.
i doubt very many self builds add in relays or other circuitry to disable the habitation circuits when the engine is running.
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