You'd be better off using a dc power supply for the laptop. I bought one at
Radio Shack a few years ago; the particlular model was on clearance for
about $20, but they usually sell for around $40 to $60, I believe. That way
you've got dc power from your battery or alternator powering dc load (your
laptop). It's the most efficient way to go. Otherwise with an inverter,
you've got dc from the van converted to ac at the inverter, and back to dc
for the power supply for the laptop. You use more power because of the
ineffieciency.

Ed in CT

>  Does an invertor keep drawing current even if there is no AC item plugged
> into it?  I'm using one
> to keep my laptop up on an extended trip.  My little invertor is rated at
> 140W sustained power, so
> it won't often keep up with the laptop draw if the laptop is on...but if I
> am not on with the
> Inspiron, it will charge up the battery in the notebook..
>
> so I sometimes just have left it plugged in and charging..but I also
> sometimes find my Aux battery
> (a small regular starting battery) goes completely flat...Should I make it
> a point to turn off that
> invertor if it is not running an AC accessory?
>  Thanks,
>  Don Hanson
>