Inverters....?

[TommyB260971]

Hi People,
This weekend I decided brave the weather and to do the first overnight camp of the year. I had already had fitted in November a new 6kW inverter and new 115a/hour leisure battery.
Off to the Lakes we went with me convincing the missus and little one that if (ha!) it got cold we could just plug the fan heater into the new inverter and we'd be toasty!!

After a walk round Ambleside we went back to the van and seeing as all the windows had frozen up we decided to plug in... 10 seconds later the inverter started bleeping and turned itself off .

I tried the battery switch and all was ok (3 lights). I tried the fan only with the heater turned off and it ran ok but as soon as the heat switch was turned on it just bleeped and turned off.

The inverter was not a cheap one (about £300 if I remember rightly) and I got a 6kW with3kW continuous for the missus' hairdryer and a little 2kW oven I bought.

Does anyone think there's a fault on the system or will it just not work on that size battery?? I checked that it's charging ok when I got home and it seems to be ok. I put my volt meter across my battery and it physically counts down when I turned the heater on 12.3 12.2 12.1 etc. when it gets to 11v it turns off!

Any advice would be welcome or similar experiences...

[72BUG]

You just simply can't pull that amount of power from a 115ah leisure battery. It will go flat in a matter of minutes. I'm sure someone will be along shortly with a more technical explination but suffice to say you're expecting far too much from a leisure battery.

[TommyB260971]

Will it?
Do you know what sort of battery size I will need or should I just give it up as a bad idea??
Thanks

[72BUG]

Will it?
Do you know what sort of battery size I will need or should I just give it up as a bad idea??
Thanks

Give it in as a bad idea. Unless you have an electric hook up then electric heaters are impossible to run effectively. You need to be looking at gas, petrol or diesel powered heaters which vent externally, such as Eberspacher, Propex or Webasto systems.

[TommyB260971]

Nice one, I'll have a look at putting a gas one in I think. Bit of a waste of money there then. That'll teach me not to research it before I put it in!!
Sounded like a good idea at the time! So there's not alot I can actually do with it is there?

[dansimpson]

For each 1000watts you pull out of the inverter you need a little bit more than that going in, 1000 watts from 12 volt battery is about 84 amps, so a couple of mins is about alll you'd expect, and I dont reckon it'll do yer battery anygood mate.
Dan

[72BUG]

Nice one, I'll have a look at putting a gas one in I think. Bit of a waste of money there then. That'll teach me not to research it before I put it in!!
Sounded like a good idea at the time! So there's not alot I can actually do with it is there?

I would certainly keep hold of the heater for use on a campsite with an electric hookup. No point burning your own fuel when you're paying for the pitch anyway. If you don't have an electric hookup on your van you can buy a simple lead from ebay or a caravan shop which will have a hookup socket on one end and a normal 240v 3v pin plug socket on the other. Some of the better ones even incorporate a trip switch for extra safety.

[TommyB260971]

Thanks Guys,
Just been on ebay to try and find one.. Plenty on but big money for a new one!

From what you say Dan I'll need a BIG BIG battery for what I thought I could do... Should of asked first eh?

Well thanks for the advice, I'll have to raid the piggy-bank..again!
Cheers

[dansimpson]

Nice one, I'll have a look at putting a gas one in I think. Bit of a waste of money there then. That'll teach me not to research it before I put it in!!
Sounded like a good idea at the time! So there's not alot I can actually do with it is there?

Charging/running something like a laptop would be fine, check the watts on any item you want to plug in, divide watts by 12 to give amps it'll approximately draw, couple of amps fine, get near 10amps and I wouldnt want to use it for long..

Dan

[TommyB260971]

Cheers Dan,
Wish I'd known that at the time! Lap top it is then.
Just a quick one.. If I have an appliance thats say 800w do I divide that by 12 to get amps?? I know I'm being a bit thick but I am from Lancashire!!
Tommy

[dansimpson]

Thats it mate, whatever watss you want to pull out, divide by the input volts, 12 is near enough, that gives you the amps. Also, as a "rough" guide, your 115amphr battery , when new and fully charged the spec is 115amps for 1 hr (not recommended you draw this high current as it'll damage yer battery), or look at it like 10amps for 11.5 hrs - but this is theoretical and in practise you'll get less than this.
Dan

[TommyB260971]

Thanks alot Dan, and you Martin!
Tommy

[Plasticman]

fleabay the inverter, get some monay back , buy a quality regulator for running laptops and the like, as^^^ says get 240 hook up and buy a gas or derv heater,
mike

[TommyB260971]

Good thinking Mike, though I'm trying to stay off fleabay due to the vast amounts of crap I tend to aquire!! I've got hook up so just looking for a heater as the erberspacher is missing from my van!
Cheers

[Plasticman]

Aye, nowt wrong with the bay but come here first for bitsm, then advice on what to get and what to pay then hit the bay fore armed and warned..
mike, whereabouts are you