Possible to keep the hab electrics on while driving?

Guigsy said:
I think it's unwise. The voltage goes all over the place while cranking.

With our dumb panel that's a bunch of mechanical switches... we leave all our circuits on all the time and haven't had an issue (yet).
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Why would the leisure circuit voltage change whilst cranking? A split charge system only connects the two circuits together when the vehicle alternator is generating whether using a simple relay or a complex B-to-B unit.
With a Battery to Battery unit the leisure side always has controlled voltage anyway so no problems should occur.

I was always lead to believe that the idea of disconnecting the leisure circuits when the vehicle was running was to try to ensure that any appliance in the habitation area could not affect modern electronics in the base vehicle by electromagnetic fields, voltage surges or spikes etc. However I think experience has shown that this is does not occur.

If you have a compressor fridge then there must be an 'always live' circuit available so I guess most suppliers of control systems make allowances for this.
 
rod_vw said:
Why would the leisure circuit voltage change whilst cranking? A split charge system only connects the two circuits together when the vehicle alternator is generating whether using a simple relay or a complex B-to-B unit.
With a Battery to Battery unit the leisure side always has controlled voltage anyway so no problems should occur.
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The electrics in my van were fitted by an aftermarket conversion company for the previous owner. The system is simple, it just connects the cab battery to the hab battery with a relay whenever the key is in the first position. I haven't even found a diode, I think it's a straight connection.

There's a 20amp fuse between the batteries, but quite a lot of current flows just when you flip the key just because of the voltage difference between batteries. And I guess it means both batteries must be pushing the starter motor? I don't quite know why it hasn't blown the fuse. But it's been working fine for the past few years.
 
rod_vw said:
If you have a compressor fridge then there must be an 'always live' circuit available so I guess most suppliers of control systems make allowances for this.
Click to expand...

For my 3-way fridge, even with the domestic power 'Off', the fridge still receives 12V when the engine is running, so I switch the domestic panel to 'Off', select 12V on the fridge and drive - and the fridge stays nice a cold.

For a compressor it's probably the same TBH.
 
Hopefully stevewagner can share his secret (y)

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The NCC don't give a stuff about end users. We are not their concern. They exist only to protect the interests of their members. <full stop
 
Our 2017 Dethleffs was wired from new in such a way that the fridge would not work even while driving unless the 12 volt power was on as the control panel was not powered.
 
I'm pleased our van switches everything off automatically, we'd be driving round with all sorts on otherwise. ?
 
Guigsy said:
The electrics in my van were fitted by an aftermarket conversion company for the previous owner. The system is simple, it just connects the cab battery to the hab battery with a relay whenever the key is in the first position. I haven't even found a diode, I think it's a straight connection.

There's a 20amp fuse between the batteries, but quite a lot of current flows just when you flip the key just because of the voltage difference between batteries. And I guess it means both batteries must be pushing the starter motor? I don't quite know why it hasn't blown the fuse. But it's been working fine for the past few years.
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If wired correctly it should have a relay for the fridge another one to charge the hab battery. Both relays should be operated by the D+ terminal on the alternator so they only work when the engine is running.
There is limited amount of power you can take from the D+ and as modern vans have loads of things switched by the D+ the converters fit relay control boxes in line with the D+ so as not to overload it.
 
We've a 2004 Bessacarr and I unplugged this wire located near the battery and all internal electrics now work with engine running. Only downside is step doesn't retract when engine is started but we can live with that.

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Tom A said:
We've a 2004 Bessacarr and I unplugged this wire located near the battery and all internal electrics now work with engine running. Only downside is step doesn't retract when engine is started but we can live with that.
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And if I were you I would check that your fridge still works on 12 volt!
 
robnchris said:
Hi Eddie, which inverter would you recommend? the slow cooker whilst travelling sounds like a fantastic idea. Cheers Rob
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Depends what you want it for. A slow cooker is not particularly highly rated and doesn't require a pure sine wave so any 50 quid inverter off ebay will run it. If you want to run other things though its a different story.
 
Find the charge relay, find the activation wire, cut it in half and fit a dash switch to both ends.. Voila one live hab battery while driving... but not charging.
 
tonka said:
Not on an Autotrail or most other British made Van's. It's some sort of guideline that the UK manufacturers seem to follow. However contintal Van's don't do it and the jab power works while in motion.
Easiest thing is to run a separate fused feed off the habitation battery and fit in your own USB/ 12v power sockets for direct power.
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I can confirm that the hab electrics work in our Wildax while on the move.

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And is yours a Sargent EC500 too?
 
Thanks for the insight!

Seems vehicle specific though, not sure I'll have said relays behind that panel.

I shall investigate (y)
 
I haven't read all the replies so this may have already been answered but when we had a compass van I asked this question and according to answers I was given was that there is a wire that runs up the door post and if you cut it and insulate it, it cures it but must confess I never did it.
 
stevewagner said:
Hi

It's not my secret I found it on here. It worked on an Autotrail Apache I had. We have a Carthago now and the habitation electrics stay on when driving.
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Thanks Steve, I know this was not your document, though I’m not quite sure what this does when the author said, switch it on when need to use the B2B etc. I thought the idea was to keep 12v running all of the time in the hab, even when is engine running. Thought that would mean using 12v whilst the engine was running and the B2B was charging too.

As for doing the wife’s hair whilst holding a torch - paint me confused ?!

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IanRJ said:
Thanks Steve, I know this was not your document, though I’m not quite sure what this does when the author said, switch it on when need to use the B2B etc. I thought the idea was to keep 12v running all of the time in the hab, even when is engine running. Thought that would mean using 12v whilst the engine was running and the B2B was charging too.

As for doing the wife’s hair whilst holding a torch - paint me confused ?!
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Sorry folks, just reread that doc and it makes perfect sense. Iam an idiot!
 
I never even thought the 12v electrics in hab area would not work while engine is running.

In our N&B they do, because the laptop sits on the bed(next to bulkhead) re-charging while on the move and is 100% on arrival.

Geoff
 
nicholsong said:
I never even thought the 12v electrics in hab area would not work while engine is running.

In our N&B they do, because the laptop sits on the bed(next to bulkhead) re-charging while on the move and is 100% on arrival.

Geoff
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It is very much a British thing. The NCC requires it, largely as a throw back to caravans. The rest of Europe aren't that daft and realise that caravans and motorhomes are used in very different ways.
 
peterc10 said:
It is very much a British thing. The NCC requires it, largely as a throw back to caravans. The rest of Europe aren't that daft and realise that caravans and motorhomes are used in very different ways.
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Don’t think it’s an NCC thing as our Adria is NCC approved and the 12v hab side works while we’re driving along.
 
This thread from another forum explains the reason and as it does have some safety aspects I would be concerned about changing things

Why disable the Habitation 12v electrics when the Engine starts?

We are working on a Elddis Encore Motorhome where the Motorhome owner wants to be able to Start the engine so the Alternator can provide upto 60amps to the habitation batteries when he operates the Invertor. By 'powering up to half' his Inverter from the 'Alternator'. His batteries, although stil...
forums.outandaboutlive.co.uk
 
Hi there
I did this fix on my Kontiki and it works A Ok.
The fridge works on 12v, however the electric step will not automatically close on ignition start. You will have to close it manually before moving off.
I know this method works for Fiat Ducatos it may well be the same for others:
... inside the engine compartment there is a fuse box holding two grey square relays .. when you turn on the ignition it activates one of the relays and that relay disconnects the electric feed for habitation area.
Turn off the ignition and the power to the relay is disconnected so power is returned to 12v habitation electrics
Its a very simple job to pull out and blank the wire that powers this relay on start up .. and Hey Presto all hab electrics work while travelling BUT REMEMBER TO PUT YOUR STEP IN before moving off.
I won't argue the rights and wrongs of electrics on the move but my granchildren loved watching 12v tv on the move.

I have a wiring/relay identification instructions somewhere if you wish to pm - start a conversation with me, I'll dig it out and pass it on .. it's so easy.
 
pwilmo said:
Hi there
I did this fix on my Kontiki and it works A Ok.
The fridge works on 12v, however the electric step will not automatically close on ignition start.

I have a wiring/relay identification instructions somewhere if you wish to pm - start a conversation with me, I'll dig it out and pass it on .. it's so easy.
Click to expand...
Indeed you offer of the instructions would be gratefully received TIA

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