Club 80-90 Forums

Hey guys. What I would like to know is... If I have a 240v appliance that is 120w and I plug this into an inverter what would the amps be at 12v?

I understand Ohms law but not sure how to apply it to this.

10 amps.. plus the inverter wattage

It's Watts divided by Volts = amps

120/240 =0.5 amps then the amp's that the inverter uses

0.5 amps at 240 v, but will still be 120w at 12v which = 10amps

dansimpson wrote:0.5 amps at 240 v, but will still be 120w at 12v which = 10amps

Which is why I cringe when people say they have a 1 or 2 Kw inverter, pull out 2kw on yer battery = 166amps

dansimpson wrote:0.5 amps at 240 v, but will still be 120w at 12v which = 10amps

but the pull on the inverter would be 0.5a then what the inverter uses surely ???

I have a 400w inverter.

to be honest I avoid inverters like the plague horrid things that flatten battery's in my opinion, what is it you want to use it for ??

jamesc76 wrote:

dansimpson wrote:0.5 amps at 240 v, but will still be 120w at 12v which = 10amps

but the pull on the inverter would be 0.5a then what the inverter uses surely ???

Nope, drop the volts the current needs to go up to keep the wattage the same, look at it this way, if you are trying to pull 120w of power out of it, you need to stick at least 120w in, and this doesnt account for the losses in the inverter circuits

ohhh i see cheers like I put above I avoid um!

jamesc76 wrote:to be honest I avoid inverters like the plague horrid things that flatten battery's in my opinion, what is it you want to use it for ??

I have everything running on 12v. I have a two very nice solar panels. But please don't laugh too much!!! I was considering using an electric blanket in the poptop to take off the chill before bedtime.

not got a propex / ebber or hot water bottle??????

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jamesc76 wrote:not got a propex / ebber or hot water bottle??????

Got an Eber but after sitting downstairs in the lovely warmth it provides, going up can feel a bit damp and cold. I'm really not a pansy but I work in the cold so last thing I want is to be cold in my time.

Just an Idea that doesn't seem too silly.

need a thermal wrap round the tent, then the heat will stay in the van and not dissapear out!