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Newbie question, so go easy on me.

If we use are caravan on a site that has EHU, can i remove the battery to lower the towing weight. Will all the electrics still work?

Cheers Adrian

MMMmmmmm good question Alladin.

we've never had a battery dont see the point if only going to sites with ehu unless theres a power cut of course

Quote: Originally posted by Alladin on 06/6/2008

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If we use are caravan on a site that has EHU, can i remove the battery to lower the towing weight. Will all the electrics still work?

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I thought that I knew the answer - and I thought that the electrics would work until recently.  

I have a battery isolator in the caravan which I fitted when the van was new to prevent the battery draining when the caravan is in storage.  When we pitch, I usually close the isolator to connect the battery before connecting the EHU cable.  The last time I went away, I forgot and connected the EHU cable with the battery still isolated.

The power system/charger kept trying to initialise, the needle on the voltmeter rose to normal but then fell again.  It kept trying every few seconds until I realised what the problem was and closed the battery isolator.

So the answer for my caravan, which is a Burstner S500TS is no, the electrics do not work if there is no battery (or if it is isolated).   The only way to tell for your caravan is to try it - or maybe read the handbook or ring the manufacturer.

Cheers
Andrew

Quote: Originally posted by tentmad on 06/6/2008

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i thought you needed the battery there for the 12v items to work as the ehu charges the battery and it takes the power from that?

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Quote: Originally posted by Alison Collier on 06/6/2008

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Some older caravans need the battery to make some of the interior lights work. Our last one was like that. The leisure battery was knackered and wouldn't hold any charge but we had to leave it in place to run the lights.

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Quote: Originally posted by rushallmanor on 06/6/2008

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Depends on the caravan make

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I thought it would depend on the charger fitted?

As long as you dont draw more than the chargers rated output you dont need a battery. I had always presumed you need a battery because the chargers only supply 4,6 or 8 amps.  A couple of lights and the waterpump would soon exceed that figure so a battery is fitted to smooth the power output.

If you have a 6amp charger & try to draw 8 amps either the voltage will drop or the charger will trip/overheat. With a battery fitted you will be taking the excess from the battery which the charger will top back up when you are using less than 6 amps.

Does that make sense?

That was the reason given to me when I bought my van new in 2005.  "The van can operate without a battery, thats why it does't come with one.  All the 12v stuff will run off the mains hookup without a battery being in place'

Couldn't tell you if it's the same for all vans.

think it is a bit of a false economy to run without a battery as all it takes is for some so and so to trip the leccy during the night and you have no lighting or waterpump. yes it does add a bit of weight but without it you are literally in the dark

also you can use sites that dont have EHU for example most racetracks in my case, just charge the battery at home and you are okay, gas for cooking, heating and hot water. having said that I reckon that if I was using the van myself I wouldnt bother with the water heater just boil a kettle to get a wash

A lot of confusion and mostly caused by thinking 'battery charger'

From around 1993 many UK vans were being fitted with a 12v 'power source' this carried on until a couple of years ago when some vans got more of a battery charger that a power source, albeit their very similar.

A battery charger proper must be capable of providing approx 14.4V to fully charge a battery, it then must have good control to switch it back to approx 13.8v to keep the battery high but not over charge and do any damage.

The main difference then is; battery charger is 14.4v/13.8v and a power source is conveniently set at the lower 13.8v. Because of this the charger always needs a battery or the control will go haywire!, but the power source being set can work on it's own and do a fairly good job of charging a battery when fitted.

The other big difference is how many amps either can supply, 10A or above is needed to run the 12v stuff without real problem. So either type with less that 10A output is going to need a battery to cope with usage.

So answer to the question is it all depends on exactly what you have installed