# 12v - 240v Inverters



## SunsetSeeker (Dec 1, 2008)

Hi Wild Ones,

Hope someone can help me out.  I am thinking of buying an inverter and have what is probably a simple question.;

I have an 85a/h battery and an appliance that pulls 100w

On 12 volt supply that gives 8.5 amps which would flatten the battery pretty fast

On 240 volt mains supply that is approx 0.42 amps.

Question. If I used the inverter what would be the impact on the battery? Would the appliance pull 0.42 or 8.5 amps per hour??

Ta in advance

Bill


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## Biker Jeff (Dec 1, 2008)

I think you've answered your own question.... it will take 8.5 amps from your battery, unless you are on hook up in which case your charger will keep the leisure battery charged up to maximum.
Your 85 amp/hr battery will be low quite quick and will not have enough power to run the inverter in quite a short time.


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## SunsetSeeker (Dec 1, 2008)

*Still a bit confused*

 Thanks Biker Jeff.  So am I right in saying that although the appliance would pull 0.42 a/h at 240 volt , if powered by an inverter it would still pull 8.5 a/h at the battery?

If that's correct the inverter would actually make things worse as it would itself pull power on top of that used by the appliance - is that correct??


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## Biker Jeff (Dec 1, 2008)

Yes.... the inverter will pull power on top of the appliance you are running through it.


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## Biker Jeff (Dec 1, 2008)

Unless you have a couple of 110amp/hr batteries and solar panels, inverters are really only any use for low power items such as phone chargers, portable DVD players with a small screen, or even low powered laptops.
But many of these low power appliances you can run on 12 volt with an in car 12V cigarette lighter plug anyway, so it sort of defeats the object of having an inverter.


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## SunsetSeeker (Dec 1, 2008)

*Thanks a lot Biker Jeff*

Thanks for that - must have been having a senior moment on that one.


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## Biker Jeff (Dec 1, 2008)

Yer welcome.


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## bevo (Dec 1, 2008)

*inverters*

hi sunsetseeker
                     that takes me back to my school days (45 years ago) and the old ohms law formula.
    watts equalls volts times amps, so amps would be watts divided by volts.
just use that formula and you can't go wrong.


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## Deleted member 2636 (Dec 1, 2008)

Fit another Leisure battery or two for a start. 
If you want an inverter this chap may be worth an email

This is the man who does the batteries and Inverters

markverney at msn dot com

At = @
and
Dot = .


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## messenger 2.5td (Dec 1, 2008)

*Inverters*

Take a peek at the Maplins website at www.maplins.co.uk type inverters in the product search tab,has a faq section could be useful for a buyer,Andy.


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## lenny (Dec 1, 2008)

Hi, Sunsetseeker, as an example my 500 watt inverter just about flattened my 85 Ah leisure battery after about 2 hours on my laptop (AC adapter.. 240 volt input.  19 volt output), last weekend


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## Deleted member 2636 (Dec 2, 2008)

If you are going to have an Inverter then you are going to need more battery capacity. A minimum of 120A should be sufficient if all you want to do is charge a laptop, camera batteries etc.
When it does get more desperate is when you want to power things like Microwaves, electric kettles*** and the like.
The quality of the affordable (for affordable read cheap 'n nasty) Inverters can be pretty suspect; unfortunately, the good stuff has never been cheap. 
If Mark Verney, see my previous post, is still in business then he gets a steady supply of really good kit

*** why people should want an electric kettle when they've got a perfectly good stove beats me but you see loads of Motorhomes with them


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## Biker Jeff (Dec 2, 2008)

I thought people only used 240 volt appliances when they are on hook up at a site.
I've got 240 volt kettle, toaster, microwave, twin electric hob, iron, and halogen heater permanantly stored in my van. When they charge 3 to 4 quid a night hook up at a site i'm going to jolly well use it. Also LCD TV and DVD player.... but i can do without all this stuff if i'm wilding.


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## SunsetSeeker (Dec 2, 2008)

Hi Wild Ones,

Thanks to everyone who offered advice.  I think I will just rough it a bit when wilding and use hookup when available.

I was a camper for 40 years so I'm used to it.  Finally having a solid roof over my head is a major step forward.

Only recently purchased the van and have tried it out a few times but not done any real wilding yet.

Happy wilding - hope to bump into a few of you soon.

Bill


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## Deleted member 2636 (Dec 2, 2008)

Biker Jeff said:


> *I thought people only used 240 volt appliances when they are on hook up at a site.*
> I've got 240 volt kettle, toaster, microwave, twin electric hob, iron, and halogen heater permanantly stored in my van. When they charge 3 to 4 quid a night hook up at a site i'm going to jolly well use it. Also LCD TV and DVD player.... but i can do without all this stuff if i'm wilding.



*my bold* You'd be surprised the number of people running microwave ovens off Inverters. The trick seems to be to try and get one of the older 500w models


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## nowhereman (Dec 2, 2008)

Dont have much cause to use an inverter, but we do have a Halfords power pack 200. This is able to jumpstart a vehicle with a flat battery (as long as it detects a residual 2.5 volts). Also has air compressor for tyres and a 300w inverter all in a handy compact portable unit. Have used it for laptop for a few hours no probs. Can be charged via 12 or 240 volt, tis a handy piece of kit.


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## Neckender (Dec 4, 2008)

We have two 85 amp leisure batteries & a 800watt inverter, we rarely use hook up on week ends away, We run a 240volt 15" lcd tv dvd, and a slow cooker now and then. We have diesel heating, which uses some current and the usual 12 volt accessories and we have never run our batteries down. The inverter cost £43 two years ago from Macro, we wouldn't be with out it. I also brought a genny 4 years ago and have only used it once and that was on our then Mazda bongo. used the inverter in our Auto Sleepers coach built and now in our Tribute 650. All horses for courses.

John.


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