Ah, the 1/2 amp is on the output side of the inverter. The input side will draw 6 or 7 amps at 12 volts (6 amps X 13.5 volts) = 81 watts.

 

Not the one in my 03' civic hybrid. I think it was rated at 10A or something. Maybe 15, but I don't think it was that high.

 

It may be rated that way, but ten bucks says it has a 30A fuse in it. It's pretty common anyway.

 

I've replaced it. It isn't 30A.

 

I always thought the majority of auto cigarette lighters used 10A fuses.
The auto manufacturers don't want you using a giant DC/AC converter and then plugging in something huge, like a portable air conditioner
THAT could kill an alternator or battery.

 

Geez, I've just seen a lot of them with 30 A fuses, that's all. Yours may or may not be 30 A.

 

i'll check what amp fuse it is and see. If it is only 10A is there any issues with dropping in a 30A fuse or will a 30A fuse even fit in that slot? thanks for all the great info.

 

Yes there are definitely issues with that. If it's designed for 10A then the wire and other components used are probably designed for 10A. You need a 10ga wire for 30A and if yours is fused lower it probably has smaller wire. Stepping up the fuse is a definite fire hazard.

 

There's a universal notebook and cell phone power adapter called the iGo Juice, which has a cigarette-lighter plug in option, in addition to adapters that plug into standard home outlets and those that plug into first-class airplane seats. It fits most notebooks.

I have one at home, but I've never used it in my car to power my notebook. It might be safer to use than a power converter? But it will cost you around $90 without shipping or tax on Amazon.com.

Amazon.com listing ($90.11 on sale)
iGo Store listing ($119.99 list price)

Just a thought.

 

For future reference, on the question of the alternator (if you were driving a car that had one) burning out because it's "running continuously": alternators *always* run continuously, at a higher voltage than the 12v storage battery -- typically 14.4 volts. The alternator always supplies all power to the car while the engine is running, unless demand rises above the alternators rated amperage, in which case voltage will sag (voltage varies inversely with amperage for a given watt output) down to the battery's 12v level, where the battery will then contribute additional amperage. If you were to do that all the time, you'd burn up both the alternator and the battery quicker. But you'd also notice things like dimmer-than-normal headlights.

But your standard cigarette lighter inverter (max 15 amp draw) isn't nearly enough load to even mildly trouble an alternator or an IMA unless you were simultaneously running headlights, wipers, both engine cooling fans, A/C, and heater blower. (And the IMA runs so much voltage it won't notice it even then.) And, in turn, a laptop power supply shouldn't overly tax a 15 amp inverter.

So, I wouldn't worry about it, and I doubt very much you'll see any change in FE from using it -- certainly no more than you see when you turn on your parking lights, because that's about the equivalent amp draw.

cheers --
doug