Hi sorry for bring up the electricity subject again but the search facility is not working at the moment and had a quick look around but couldn't find if anyone has tried using one of these 150W DC 12V to AC 240V Power Invertor http://www.maplin.co.uk/module.aspx?TabID=1&criteria=usb&ModuleNo=218810&doy=search&C=SO&U=Strat15#Faq as my son is talking about buying one from Maplins and I wanted to find out first if anyone has tried one and how much can you run on one and how much does it take out of the car battery etc you know all that tekky talk.
Don't even think of running anything like that off your car battery for more than a few minutes unless you've got the engine running. Car batteries are designed to be kept fully charged ready to start the car; if you flatten it you WILL shorten its life or kill it dead.
There are specialist batteries called 'leisure batteries' that you can use (they can suffer deeper discharge) but then you have all the hassle of carrying an extra battery and charging it.
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The simple answer is that it will power anything needing less than 150watts, which isn't a lot, maybe a laptop or game station. Then power requirement in watts should be on the label of anything you are thinking of.
It'll completely flatten an 85Ah battery in about 7 hours at full power
If you use a car battery, you might well be pushing it in the morning!
Leisure batteries are completely different construction to a car battery. Neither will run one of these for long. Both will be ruined if you run them "flat". If you need 240V then you really need a hook up.
I have the 300 watt version of this, i think that you will find that when the battery has discharged to a certain level the inverter will cut out, don't quote me on this but i think it does this both to protect the battery & leave it with enough power to start the car. I run mine on a 85amp leisure battery which runs a hi fi on fairly loud for 8 hrs a day (on a market stall, not campsite) for two days minimum
Hi a 300 watt is more useful than the 150w but as mentioned they will turn off normally when the battery drops to 10.5v this avoids damaging the battery, a leisure battery is the correct battery to use, though it will fine on a car battery.
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