I have a tc4400, 2.0ghz core2, 3gb ram, etc. Normal use for me at the lowest screen settings is about 2.5-3 hours with the battery only being a few months old. Even out of the box with wifi off and brightness down I only got 3.5 if i was lucky. If you need to use it all day without plugging in it looks like you’ll need 2 extended batteries to add to the standard.

I have a tc4400, 2.0ghz core2, 3gb ram, etc. Normal use for me at the lowest screen settings is about 2.5-3 hours with the battery only being a few months old. Even out of the box with wifi off and brightness down I only got 3.5 if i was lucky. If you need to use it all day without plugging in it looks like you’ll need 2 extended batteries to add to the standard.

Even with screen brightness at minimum and WiFi off, I’m getting 3-4 hours max. And I squint a lot while working.

Got to tell you, I have a tc4200 and if I have the wi-fi off, regular business use gets me a good 5 hours of battery time. When I add the travel battery I’m looking at at… Well, actually, I can’t answer that because I’ve never gone short on power.

With wi-fi on, I’m looking at more like 2 1/2-3 hours. With the extended battery I’ve gone 4+ regularly(again, I’ve never had to push its limit).

My power settings are not very battery friendly- usually Away On, Light sensor off, and a lot of hard disk usage in signal processing. So my times are quite a bit less than a well optimized system would be.

The travel battery does add a pound of weight and I use it mostly when I’ll be in landscape or laptop modes.

Are you sure it is not on the ultra-capacity battery?

And this is dual-core.

Not exactly apples to apples but HP also promised approximately the same battery life on the previous TC4200 model. Much to my surprise, when I received my TC4200, the battery life is actually quite close to their projections. I regularly get 4:45 to 5:10 on the bundled battery with the automatic brightness option set and wi-fi TURNED ON! Has actually been one of the greatest surprises of any laptop/tablet I’ve ever used.

They are telling right. If you shut down one core, underclock the other core to 600 mhz, set the brightness to %10, don’t run wifi and bluetooth. While watching the notebook and ask yourself “what the hell i’ve done!”, you will see 10 wh on idle.

Wait, if I forget the math, then how do I add those 2 lbs? ;P

Forget the math, a 12 cell battery will add at least 2 pounds to a 4.5 pound device. That is entering Gateway territory.

Assuming “average” means “normal”, I think you can easily cut that 21W average in half by lowering screen brightness, turning off wireless connections, and going to standby every time you step away from the screen. Stay away from heavy processing, optical drive use, and hungry peripherals, and I’d think it’ll get “up to” maximum battery life. Doesn’t sound like a very productive 16 hours though.

Hi JK.

You’re right with your maths.
and they’re probably right with theirs too.

To get 5hrs and 30 mins from a 55W battery, it needs to take 10W. In theory, that CPU with an efficient screen and good components could easily achieve 10w drain at idle. (If you turned the screen off, you’d probably get more than that too but I guess they draw a line with their creative maths at ‘unuseable’)

Minimum life on the device is probably going to be around 2 hours (playing a big DivX for example)

Table 19 on this doc gives some good info about power ono this CPU.
http://download.intel.com/design/mobile/datashts/30922102.pdf

Steve.