T400, P8600, WXGA+ CCFL, 6-cell batt. = 4 hour battery life?

Hi all,

Got a new T400 with P8600, 1440x900 CCFL screen, 6-cell battery, Vista Home Premium 32-bit, Intel 5300 wifi.

With wifi on, very light intermittent internet browsing and the screen at max or one notch below max brightness, I manage about a 4-hour runtime. Is this about right? I've read reviews where they get almost 6 hours on the 6-cell battery, does anyone else see that kind of battery life?

I've already disabled all the things I don't use from the BIOS, i.e. the modem, the firewire, parallel/serial ports (what are these for anyways?), cpu on battery-optimized, mostly idling when browsing.

I'd also really appreciate if anyone can share their battery runtimes with stats (wifi on/off, screen at what level of brightness, battery size, etc) so I can see whether I'm in the norm or not.

Cheers.

P.S. I'm also really curious about what the parallel/serial ports are in the bios. I've disabled both of them and nothing has been affected...

 

4 hours sounds about right for a 6 cell with that usage pattern. The 6 cell is rated at 56WHr, and light internet browsing is likely to draw 12-14 watts (I can do it at 10-12, but I have a smaller LED display and LV processor). 56WHr/14 watts = 4 hours.

The best thing to do is monitor your current watt usage (battery tab in power manager). At true idle with Wi-Fi off you should be able to get slightly under 10 watts (I can get slightly under 7 due to the 12.1" LED, LV CPU, and SSD), internet browsing will run slightly higher, video playback higher than that, and gaming higher still.

The parallel and serial ports are most likely a reference to the dock. I know that at least one of the T400 docks has parallel and/or serial.

 

That's likely your problem. On a typical laptop, the screen consumes about 40% of the laptop's total power usage. Dimming the screen will greatly increase battery life, especially on larger screens.

 

Thanks guys, you've assuaged some of my concerns.

The 6 hour runtime that notebookreview got in the updated T400 w/ high-nit led review ( http://www.notebookreview.com/default.asp?newsID=4946&review=lenovo+thinkpad+t400 ) is still boggling my mind though...

I guess I'll test battery life with screen brightness down...

 

Also note that LED screens are more efficient than your ccfl

 

Initial seetings for battery on my T400 are with screen brightness set to 70%. Please try that with your laptop and see how you get along or set the power scheme back to default unless you are using an entirely different scheme. I am reffering to Enery Star plan.

Gary

 

i wouldn't really believe the review's exaggerated battery life. 11 hrs on a 9-cell? yea right.

i was using a 6-cell with xp and got like a decent 2:30,
now on vista with 9-cell i get a decent 6 hrs.

decent=half bright, wifi, lots of tabs on firefox.

should also notice that those who claim exaggerated battery life probably state them while at idle with nearly impractical settings.

 

I thought that those reviewers have programs that can "simulate" a realistic middle-of-the-road workload to get the battery runtimes?

Anyways, thanks for your battery life numbers, keltix. I've swapped out my T400's harddrive with an Intel X-25M ssd and done a fresh install of XP Home. I'll see how that goes over the next few days.

I've already ordered a 9-cell as well as an ultrabay battery. Can't wait to try those out.

 

When I use my T500 indoors during the late afternoon (so screen is set to 4 notches from dimmest) I can get more than 7 hours of light word processing and web surfing on my 9-cell. I wouldn't say that the review estimates for the T400 are that exaggerated.