Power Querie

[Angelos_374310378]

Hi there to All, i just got my caravan (1st one ever), would like to short out the power problem of mine, i intend to leave my caravan in aplot of land in corfu greece but there are no plugs around, i will need to use 4 light bulbs (12v,) a laptop running on 220v, a 12v television, a radio and a set of pc speakers of four mini speakers and a sub wofer(a typical 5 peiece sound blaster set), how can i calculate the Watts/hour/day, how may batteries i will need and what are the options to charge the batteries?

please help

Aggelos

 

[nick_374224697]

Angelos, with running all that stuff you would be better buying a generator, it will charge your battery and provide 240v power without the need for an inverter.

 

[BeemerMal]

Angelos....Nick is right If you don't have any mains power you will have difficulty running everything. And even with inverters you will run your battery down very quickly.

A petrol generator will power all your items and keep your battery topped up. These cost from about

 

[rob_jax]

Hi,

Petrol Generators:

The cheap type of generator is OK to power an electric drill, but they are lethal to modern electronic systems - with no real load or electronic stabilisation they create overevoltage spikes of 50% or more - and this will kill things like laptops, TV and music systems.

Electronically stabilised generators - like the Honda and Kippor generators are much more expensive - but they do produce clean, stable 230V supplies.

Solar PV panels:

A quiet (and free to operate) alternative is a solar panel - if you have an 80AH battery, then a 40Watt solar panel should recharge that battery during the day.

The cost of a 40Watt panel and charge controller system is going to be similar to a Kippor generator, but will only generate about 1/10 the electrical power - but it's free and it runs every day.

10 hours of sun will provide about 400 Watt / hours of electricity from a 40 watt panel - compare this to your expected useage and see if you need a more powerful panel.

Wind generator:

Often seen on sailing yachts in harbour, these work day and night (if there is wind) and a small model will recharge a caravan battery.

Most expensive option and only really work well somewhere where there is no obstruction to the wind - like the sea

Watts:

Look at the watt rating of the bulbs, add that up and mutiply that by the number of hours you think they will be switched on.

Do the same for the laptop, radio, music system, etc., and add that up.

You should now have a total in Watt / Hours for your appliances.

Divide that total by 12 volts and that will be the number of amps taken from the 12 volt battery - obviously the 230volt laptop will be powered by an inverter (raising the 12 volts to 230volts) but the watts used will be the same.

For example:

4 lamps x 10 watts x 2 hours = 80 watt / hours (WA)

1 laptop (60 watts) x 2 hours = 120 WA

Total = 200 WA

Divide 200 WA by 12 volts = 16.7 - and this is in Amp Hours - the way batteries are rated.

So a 100 AH battery will supply 16.7AH for around 6 days (actually only about 4 days - because a battery won't release 100% of the stored energy - only around 75%)

Robert

 

[ProfJohnL]

Hi

Taking Rob-jax's thoughts a little further, it seems to me that your usage is likely to be around the 300W per day.

Given that Corfu is is in the Med and is generally sunnier than the UK,solar power seems quite viable option.

A combination of a 110Ah battery with an 80 to 100Watt solar panel with an inverter (12Vdc to 230Vac) should provide you with a quiet and reliable source of power, even on the few grey days and during the winter months.

 

[Angela_5076436]

Angelos ,

Where is this caravan at pesent ?

Yaking it to Crofu from the UK will be rather expensive I would have thought .

Might well be cheaper to buy your gear [ generator etc ] when on Corfu

 

[nick_374224697]

Angelos, on behalf of myself and all the other well meaning people on this track I'd like to express the fact that it is our pleasure for helping you out. Please feel no obligation to thank us.

 

[Cathryn1]

He's gone off to Corfu already.......

 

[Angelos_374310378]

He's gone off to Corfu already.......

sorry guys, i was temporarilly on a cafe but now iam back,

So thanx for the help, i think i will go for an 150w solar paneland two car batteries hopping it will be fine, im planning to turn that caravaninto a permanent home for me in corfu were iam already...

have a nice summer gizzas