# Apparently there’s no such thing as a stupid question …….



## commuter (Jul 13, 2011)

So I’ll ask mine. Having just bought our first motorhome privately we got a good handover from the previous owner who kept asking “is there anything else you need to know?” which scrambled my brain as I’m sure there is much I do not know. Whilst reading through the massive pack of information which came with it I managed to answer all of my questions as they came up apart from one which is kind of fundamental.

Scenario – we arrive on site and decide to use EHU. The 240v light above the steps works fine when on EHU but the spotlights around the dinette are 12v and do not work when on EHU

Question – Do I flick the switch on the control panel above the door over to 12v to use the spotlights? Is the battery being charged while I’m on EHU and simultaneously draining it by using the 12v lights?

Thanks for taking the time read this and please be gentle with me


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## DSL2 (Mar 6, 2008)

Yes exactly that, plug into the 240v & then switch on the 12v to run all 12v systems such as lights & no doubt the water pump too. 

Batteries will be being charged at a much greater rate via the 240v input than you are discharging it whilst using the 12v systems!


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## tonyt (May 25, 2005)

You don't say what motorhome you have.

Have you located the battery charger?


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## eddied (May 9, 2005)

*Electrickery*

 I'm completely brain dead when it comes to elecktrickery, but I'll start the ball rolling. Normally when on EHU you can still use all your 12v. lights/sockets etc. They will take current frm the leisure battery, which in the meantime should also be being charged by the EHU.
It will depend on the model of motohome you have whether or not you need to flick any switches to achieve this. On the ones I've owned it was all automatic.
saluti,
eddied


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## weldted (May 1, 2005)

*power supply*

Hi depending on your motorhome, most are fitted with a power supply/charger. The idea being that it will supply 12volts at up to say 20 amps with any current not being used going to the batteries, so if you have halogen type lamps spot light type are usually 10 watt, roof lights may be 10 or 20 watts, so allowing for voltage loss in cabling and switches you could say a 10 watt halogen uses 1 amp 20 watt 2 amps and so on. a flat screen 17" lcd tv may use 3-4 amps so you get the picture on the balance between what goes to you battery against what you are using. It also depends on the state of your battery how much current it will absorb. The charger usually comes on by itself when you plug into the mains but you will have to turn the 12 volt supply on unless it is a older van with a manual type zig unit. The power supply/charger may be regulated at 13.8 volt called a constant current charger which will supply the power at a rate that will not cause the batteries to gas, but these do not fully charge a leisure battery as they like around 14.4. Not a problem if you are to spend most of your time on hook ups but if you like wild camping or cl without power you may wish to look at say the sterling power products site where you will find more information about battery charging, or look up solar panels to top up your batteries off hookup. hope this helps


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## commuter (Jul 13, 2011)

wow thanks for the quick replies sorry it took me so long to get back (work gets in the way of everything). We have a 04 registered dethleffs globetrotter. It's been mainly used on EHU by the previous owners so there's just a single leisure battery under the passenger seat (lhd). AFAIK there are only 2 12v sockets plus one euro cigarette lighter type connection.

We're not sure how much time we will spend off EHU so it's not really practical to start adding batteries or solar panels at the moment

More questions

- Can I add more standard square pin sockets linked in the provide more 12v connections?
- on the assumption that we are going to be on EHU would I be better using 12v for tv etc?


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## Spacerunner (Mar 18, 2006)

My policy is that when on EHU any kit that can be powered by mains is plugged into a mains socket.

BTW I found out the other day that, when on EHU, if the battery charger is switched off then no 12 volt services work  :roll:


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## rayc (Jun 3, 2008)

Spacerunner said:


> My policy is that when on EHU any kit that can be powered by mains is plugged into a mains socket.
> 
> BTW I found out the other day that, when on EHU, if the battery charger is switched off then no 12 volt services work  :roll:


John, Then you have a problem. When I am on EHU and I switch the charger off all 12v circuits function normally. That's the way it's always been in the 30 years I have owned caravans and MH's. Ray


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## Spacerunner (Mar 18, 2006)

rayc said:


> Spacerunner said:
> 
> 
> > My policy is that when on EHU any kit that can be powered by mains is plugged into a mains socket.
> ...


Sorry  Should have mentioned that I had removed the batteries too.

Premature senility is a curse of the thinking old git


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## greenasthegrass (Oct 27, 2007)

No it's a deadlegs Ray that's how they work if you flick off the 12v nowt works!

Greenie


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