Battery power question?

[deportes]

I am using my laptop fwhile sitting in y truck via a power inverter, and connecting to the web via a city wifi connection, how long do you think the truck battery will last before I need to start the truck again.
The radio is off and no ancilliary stuff running other than the laptop.
Thanks.

[allaboutmusic]

A good power inverter should warn you before the battery gets too low.

[deportes]

thanks. i am googeling the question and I need to figure how many amp/h the laptop uses, not sure. May need to hook up a amp metere to find out.

[allaboutmusic]

Does the adaptor give any figures? Wattage for example?

[deportes]

Yes, the laptop adapter indicates 4.9A and 90W, what the calculation for amp hr I'm not sure. Thanks.

[allaboutmusic]

Lots of calculators on the web if you're rusty on your physics formulae.

http://www.bigfrogmountain.com/calcu...phourusage.htm

[Redlemon]

Just keep posting every half hour, deportes. When you stop posting, we'll know the answer.

[allaboutmusic]

Ha. Not quite true - he'll still have battery reserve power after that.