I'm trying to make an educated guess concerning the battery life. I already ordered the 8790 with the 8-cell because I wanted to put the other $130 towards something else on the configuration.
Now, part of this is my guess for battery life concerns my Sager 8500, which, when balanced with my server, is still my main computer. I think all batteries in the 8500 are 8-cell. I have no idea, which is why I am asking.
The 8500's battery, even three years later, lasts well into the 2 1/2 hour mark without tweaking or sacrificing performance. This is in part because the PIII has speed-stepping on it (at least, that would be my guess). However, I loaded a battery monitor application and it noted my CPU was running at the same clock speed as when it was on AC. This means, at max performance, the 8500's battery lasts 2.5 hours. Assuming the P4EE also has some sort of speed stepping (I forgot if it did or not), I would think the same cell battery as the 8500 may last 1.75 hours to 2 hours in it.
Now, if we have the wireless card active, you will see a steep drop in this power estimate. My LinkSys A+G card is always set to full power and sucks about .5 to .75 hours from the battery when connected. Ouch.
However, all this estimation is based on the 8500's battery cell count. So, does anyone actually know how many cells are in the 8500 to complete this equation? When I receive new laptops, I always charge them up to full power first (or set the system up while on AC with the battery out), and run the battery dry three or four times straight. I will be certain to time how long the 8-cell battery lasts during this time. If it lasts less than 1.75 hours, it's time to buy the 12-cell.
Also, I wonder if the 8790's battery is hot-swappable when on AC power. Are any tools needed to take out the TV tuner and battery?