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I am pretty new to caravanning and would appreciate any help about the subject.

I want to be free from 240v mains electric so I am not tied to a hook up. However, I still want to watch TV(I have a normal 240v one-portable colour and don't really want to pay for a 12v one which I think take up less power(?) and seem to cost a fortune).

I have been told to get an invertor to plug the 3 pin plug from the TV into. However Ihave also been told that I will be only be able to watch a couple of hours of TV before the battery goes flat.

Could anyone suggest what is the most efficient(and cheapest)way of doing this as I dont want to take 20 batteries away with me or have to charge the leisure battery every day. Lights, water pump and Carver switches for heating and water will also be used.(Ive got a feeling the kettle,fan heater and iron are out the question here!).

Also, any clues on what is the best size leisure battery to use(amphours)and how long it would last and how long it would take to charge up.

Also, what charger should I buy to do an adequate job of charging the battery.

Any good websites to purchase these things?(invertor,charger,battery,powr packs,12v TV)

Last one honest!- I have seen an all in one invertor/battery(I think they are called power packs/stations) - is this the better option as it seems this could rid the need to buy a leisure battery and charger?

Hope you can help

kTANGO

Welcome to UKCS.

If you are planning on using any form of 'artificial' power supply for a telly forget it. As has been said, it's a couple of hours at the most!

Why do you want to avoid 240V. Most sites have hookup points nowadays.

Karl

Hi,

Maybe ktango wants to go only on rallies where there are no hook ups.

I am sorry I can't answer your problem but I am sure someone will answer your question soon

I'm afraid there is no "nice" answer to this one.

As an electrical engineer, I can give you some reasons:

Inverters are by their very nature and design, somewhat inefficient: i.e. power is "wasted" in the process of converting fron 12V DC to 240V AC. Additionally, there is no getting away from the basics of mathematics.

If a 240V TV consumes 1Amp, then applying the maths it consumes 240 Watts.

To run the same TV from an inverter/battery, the Watts remain the same, but the current needed from the battery now becomes 240 divided by 12 i.e 20 Amps!

A good 110Ah leisure battery will therefore theoretically run the tv for about 5 hours.

In practice, however, the inverter will demand more than the 20 Amps to cover the "wastage" I mentioned earlier, and a battery will rarely perform right up to it's rated capacity, so you could expect less time than the theory suggests.

Other disadvantages are that the inverter is bulky and chucks out a lot of heat. Also carrying a 110Ah battery is no joke!

The best solution is to buy a (more expensive) 12V DC tv.

Power "station" type gizmo's usually have NiCd batteries, are of faily limited eendurance an cost quite a bit. You really are better off sticking with a leisure battery of a sensible size/weight and "cutting your cloth" to suit as far as the type of appliances that you buy.

-Lastly, (honest!) any reasonable charger from a reputable source will do to charge your battery - Most good car accessory shops will stock a later-generation charger with an electronically-controlled output. - These are the best (in my opinion), although any simple charger will work.- It's all a case of looking after the battery and keeping the electrolyte topped up. - Don't assume that leisure batteries are "sealed for life" or "maintenance free" - there is no such thing.

- Hope this helps.

Really appreciate the quick replies. This site is excellent!!

Quick reply to Karl: there are many reasons why one would not be using an electric hook up, and as Suzzie suggested an obvious one would be rallies(although that it not what I will be taking part in).

PS. I wish I had stuck in at maths/electronics as the above takes a little thinking about to say the least.

Would one of the very small TV's like the 7" screens use a lot less power than a normal colour 14" TV?

Absolutely facinated with this thread..thanks for the electronics revision classes too...forgot stuff like P= IV !

So can anyone add to this...whats the preacticality of charging the aforementioned battery with solar panel/wind power? (As recharge will difficult without hookup!)

;) Like to throw spanners in the works!

Finbar

Small TV's do use less power. LCD screen types should be checked because the gains in power reduction using LCD can sometimes be offset by the power requirements of the backlighting system. General rule of thumb is that yer gets what yer pays for..

I have tried to steer clear of getting too technical (I hate maths, I'd rather be fixing things) so did not go into great detail in my last post, or this one.

There is a lot to be said for "going back in time" a little, Our first 'van would survive a whole weekend on a rally with a 70Ah battery, BUT.. It had a Gas light, a Gas fridge, a foot pump and NO blown air, kitchen extractor, flush toilet etc. The van I have now with a 110Ah battery would probably survive the weekend with very careful use of the electrical system, by try explaining that to the kids! - As ever there is a price to pay for all the luxury items we now have in caravans, that price is increased energy demand, from whatever source.

A solar panel will, as George has said, contribute little unless it is a) huge and b) in the sun! - I know several folks who have fitted or take solar panels with them and also one or two who have bought those dinky little wind-powered generators. - My opinion? - Very expensive for the benefits gained, and those benefits cannot be relied upon in the British Isles (despite what we may think of the weather).

P=IV rules as a rule (pun intended) and the only way to go is as I said "cut yer cloth to suit" !

Cheers.