T400 Power usage on battery

[Toups]

I have noticed with my T400 integrated graphics model, no matter how low I set the power management settings the usage on battery rarely reaches (and never goes lower) than 10.2 watts?

Anyone else experiencing the same or have recommendations for further power reduction?


Thanks in advance

[aaa]

Lower the brightness if you haven't already.
Get the hard drive to spin down (use your ears to be sure).

There is also undervolting, but it's usefulness varies with each iteration Intel releases. The past few models did not benefit in terms of idle power (lowest cpu setting for example), only under load.

[Toups]

I have done both, with the brightness set to 3 with the LED backlight and the harddrive off

I think I may get one of the 128bg Samsung SSD from a new Dell pull and give that a try

[Toshe]

Yes, I have noticed it too: Power usage won't fall below 10 watts when idle. With the HDD always spinning (hard disk rotation is on const), integrated graphics and the display brightness set to 3-4 the consumption goes to about 12-18W when idle. This gives me about 3:15h-4:15h when taking notes, writing, browsing and listening to music on the 6-cell battery.
I really can't imagine how Lenovo performed the battery tests.. I mean 6,5h on the 6 cell battery sounds impossible to me. Simple math prooves that:
power consumption when idle: min. 10W per hour.
Battery capacity: <60Wh.
It's just simple physics that shout "no way this battery could last more than 6 hours."
SSD drives consume less, but price and capacity are still a problem, so many of us are going to stick with HDDs for the near future.

[mudtoe]

10 watts isn't too bad. I'm going to post this so that it becomes part of this thread in case someone else has this problem.

I have a T400 with switchable graphics running Vista Business 64 bit. I took it on the plane the other day and I got barely two hours of run time, even though I had the thing set to close to maximum power savings (I had the monitor a couple notches higher as it's almost unreadable at the lowest setting). I was using a consistent 25-28 watts even though, as I said, I had all the power savings at maximum except the lcd being a couple notches above bottom.

Afterward I was playing with it on battery and could never get a run time estimate above two hours and 5 minutes no matter what I did because it was always using a minimum of 25 watts. It turns out that the problem was that the ATI display device driver settings somehow got screwed up and the device was not usable (had the yellow exclamation point next to it in device manager). I was running on the Intel integrated graphics device the whole time, which on the surface you would think would be better for battery life. Also, I was unable to perform a "graphics switch" using the power gauge near the tray.

I ended up having to remove the display drivers (both Intel and ATI), which forced me back to generic VGA drivers, and then I had to download and reinstall the drivers from the Lenovo web site (both drivers are in the same package). It was a real pain to get the drivers to install again, as it kept reverting to the VGA drivers every time I would reboot, but I finally got them to take by actually removing even the VGA devices (not the driver, just the display devices) from device manager, and then installing the regular drivers before rebooting after the removal.

In any event, what I think happened was that when the ATI driver initially got screwed up I believe it left the ATI adapter in a powered on state even though it showed as non-operational and I was running with the Intel display device (I also suspect that the ATI adapter goes active at boot time and stays that way unless the driver tells it to shut down). I believe that having both adapters active at all times is what was consuming all that power.

I remember someone complaining in a previous thread that the T400 only got 2 hours worth of run time on battery when running from a DOS disk, and I suspect that both graphics adapters are active in that configuration and causing the same effect as two hours was my run time as well. Perhaps one could be turned off in the BIOS if that was desired for DOS or Linux usage.

In any event once I got both adapters working again with the correct drivers (i.e. not one of them using the standard VGA driver) then my run time went back over three hours with moderate power savings settings, and I was again able to use the power gauge to switch from one adapter to another.

Just thought I'd document this so that in case someone else is having only two hour run time even though they are using reasonable power management settings, I'd suggest checking device manager to make sure that both graphics adapters are active and have the right drivers loaded.

mudtoe

[SHoTTa35]

seriously? 10watts for a 14" LCD system with power CPUs such as those? My T60 probably idles around 14watts and i'd love to get it down to 10watts.

Query, for all the peoples complaining, did you come from a X series or something that can go down to 7watts? Otherwise, not even the other T4x series can top the T400, battery life and CPUs are more powerful on the T400 and you get longer battery life anyways.

[piksel]

If you are running Windows Vista Business and want to maximize your battery life, remember to turn Aero off. It cuts power consumption down by watts.

Also, turn off all services that you don't need. For example, if you don't need the vista style file search, you may turn Windows Search service off. This reduces hdd trashing which again results greater battery life.

In addition, when starting your laptop, wait for some time to see on what level your power consumption sets to. Vista seems to run startup(?) stuff on the background for 15-20 minutes after boot up and after that time the power consumption should go down.

I manage to get (on my T400 P8600, CCFL panel) under 8 watts when "idling" (firefox with 10 tabs, 2 instances of putty and inkscape open).

[amn]

10 watts for T400 is too much.

My 14" T61 with integrated graphics idles at 8. The screen brithtness is at half. Wi-Fi on. Hard drive idle and sleeping (not spinning). Bluetooth off. No applications that expect to deliver results are running - i.e. just the desktop.

The results were achieved in and after tweaking an Ubuntu 8.10.

Model number 7658CTO.

If I disable certain parts of the desktop, like temperature monitoring and certain drivers and background daemons, it can POSSIBLY go down to 7, maybe 6. Or, maybe not.

[amn]

If you are running Windows Vista Business and want to maximize your battery life, remember to turn Aero off. It cuts power consumption down by watts.

Also, turn off all services that you don't need. For example, if you don't need the vista style file search, you may turn Windows Search service off. This reduces hdd trashing which again results greater battery life.

In addition, when starting your laptop, wait for some time to see on what level your power consumption sets to. Vista seems to run startup(?) stuff on the background for 15-20 minutes after boot up and after that time the power consumption should go down.

I manage to get (on my T400 P8600, CCFL panel) under 8 watts when "idling" (firefox with 10 tabs, 2 instances of putty and inkscape open).

8 watts under Linux or Windows? The mere fact that it idles at 8 with firefox running is nothing but surprising to me. Firefox under Linux always does something, even when not reacting on user input.

Also, radios on or off? Screen brightness? Hard disk power management?

Model nr. ?

[T400plus]

Dears,
My experience and solution from some helpful gentleman(?)/lady from this newsgroup.
Keep the wake up on lan settings off.Only if you require that oddball feature enable it.
Lenovo Help in my poor country took 7-8 days even to understand the hybernating concept.so...

I own a T400 with wxga+, blutooth(disabled),wireless(disabled), wakeuponlan(disabled), a 160 gb 7200 rpm sata 1
harddisk,a useless 2GB intele made cache memory......

[kjjb0204]

Interesting. I have my T400 set on highest brightness, couple of browsers open and radios on, and it hovers between 12-14whrs.

[T400plus]

does a wxga + consume more power than just a ordinary WXga (both being CCFL flavour)

[Marin85]

does a wxga + consume more power than just a ordinary WXga (both being CCFL flavour)

Theoretically yes, because of the slightly higher resolution. But in real life I believe the difference would be negligible.

[Binh]

I don't know if it will work in T400, but in my T42p I can free up 2W by disabling the FingerPrint reader.
In T4x, if there is any device connected to USB port then the power consumption is raised by ~2W. And the fingeprint reader is a USB device. In windows XP, I go to Computer management -> Device Manager -> Universal Serial Bus controller -> disable the last USB Universal host controller in the list (I have four of these in the list).

Hope this will help.

[agarza]

My T61 can reach 9W under XP:


I'm sure the T400 can do better than that, a shame Vista is not optimized to squeeze out every bit of power on the battery, instead it just suck it up.

[cseufert]

Yer, my T400 (P8600, 4Gb, 320Gb Seagate 7200, Wifi, Bluetooth, LED BL, etc) on Windows 7 runs around 9.5~11 Watts, i flucuation is probably the hdd running and sleeping. Considering getting a OCZ Vertex (SSD) for it.

Interestingly if I plug the receiver for my Logitech VX Nano, it ups the power by around 1~2W.

I have the 9 cell battery and can get around 7 to 7.5 hours just using it for web dev work.

[jessea510]

I have a T400 xp T9500 (led 1440x900) with a Samsung SLC ssd 32gb with operating system and programs and a g.skill mlc sdd 64gb in the ultrabay hdd adapter with all my files and I get about 9.5watts on maximum battery and screen 1/3 of brightness. This is with the wireless on and bluetooth off. If i turn off the wireless and screen all the way down i can get into the lower 8s. I'm sure if i only had the one hard drive(the samsung) I can get into the 7s