Battery Recharge Time

[Zilverado]

Ok, so here's a weird one...

Typically how long would it take our trucks to recharge a battery (from virtually dead), by running the engine or driving. Assuming stock alternator, no accesories running, etc.

The reason for the question - - well, we're going camping and I'm looking to run a laptop off of a power inverter on the truck battery. Obviously the battery will need to be recharged at some points, so I was wondering how long this would take.

I am also thinking of using a deep cycle battery to avoid damaging the vehicle battery with the constant drain, recharge, drain, etc.

Any thoughts? Thanks.