Hey guys, I'm looking at running an inverter to power my laptop while I'm on site for work. I'll be there for a couple hours, tethered through my Crackberry, and already have a car charger for that. But as much as I'd like to carry extra batteries for my laptop and call it done, the applications I run run battery time down to 40 minutes at best.
That said, I was thinking I'd install a voltmeter in the car to be able to tell when the battery is close to being too weak to start the car. Is this the right way to go? What level am I looking at being unable to start the car?
I may also invest in an ammeter, since that seems to be the more realistic measurement of how much juice is left in a battery.
My current ride is a 2006 WRX. The Miata I could pushstart (minimal interior weigh-in was something like 2200 lbs, VERY easy to push start... Subby not so much at 3300+!)
Oh, and I also have a Kinetik HC1400 power cell on the way

I may order another with isolator and all the extra wiring and box to get it to the point of I can sit in the backseat with the laptop overnight music playing and crunching numbers and still go an start the car at sunrise.