How to maximize battery life of a T400?

I've read, read and read a lot of T400's reviews. A lot of them said that it can archive over 5 hours with only 6-cell battery. I tried, but only get 3 hours in average. Reduce screen brightness, turn off bluetooth,...Is there something I forgot? How can I do to maximize battery life of a T400, and still keep comfortable?

 

The same question came to my mind as well, I too get only average 3hrs in my T410, 6-cell battery.

 

Adjust the CPU throttling features in Power Manager, automatically eject the optical drive when not in use, set screen to turn off after 5 minutes (and in Windows 7, autodim after 1 minute), make sure Bluetooth is off, make sure you are on integrated graphics mode (in Windows 7, you'll need to toggle graphics after exiting sleep), etc. Disable unnecessary background processes, close the Sidebar in Vista, etc.

You should not have too much trouble getting 4-5 hours of battery out of a new 6-cell on a T400, but remember that batteries do degrade over time, and also that the measured time is from 100% charge to whenever the laptop hibernates or runs out of charge (depending on review), which is actually not good for the battery.

 

ive had my T400 for a year and a half and still get 8 hours using a 9 cell. if i really lowered all settings i can probably get around 10.

 

Make sure you have all the power manager drivers and system interface drivers from Lenovo installed.

In windows 7 open a command window and run:

powercfg -energy

It may tell you if something is not suspending properly. Although, for me, and I think all Thinkpads, "PCI Express Active-State Power Management (ASPM)" is always disabled. But your USB ports should not produce an error.

And lets go ahead and make sure your usage is the same as most of these reviews...which is low brightness, powersaver mode/lowest position on the slider, looking at basic webpages, often with no flash or with Adblock, loading a new page on average of 30 seconds.

Browsing the web, editing documents and playing music at the same time does not count as light usage (in terms of battery life anyway).

 

Undervolting your T400 should also give you a significant increase in battery life.

 

Interesting trick, I will test it.
That's funny that I overclocked (and of course, increased Vcore) my desktop and now undervolt my laptop. Really funny

 

I find that with my T400 with six-cell battery, it's impossible to achieve real-life battery life of six hours. My T400 is I suppose "held back" by its WXGA+ CCFL backlit screen and a 7200 RPM hard drive. Although I rarely charge up my battery to 100% because I usually never need that much battery life, I estimate that a full charge and discharge in actual usage conditions could give me about five hours without wireless and four hours or less with wireless. I mean, if I turn off the wireless, eject the optical drive, and let the computer idle, power usage can drop to near 8 watts flat (theoretically 56 WHr/8W = 7 hours), but even moving the trackpoint or typing will raise the power consumption. Having firefox open with lots of tabs raises the power usage of the laptop significantly because firefox uses some CPU cycles. Wireless will also add about two watts.

I use these measures to lengthen battery life.
1- turn of your optical drive with easy eject. Your optical drive may not be spinning but it is still using a watt of power.
2- turn off wireless and shut down internet browsers; these take up a bunch of power; this is the most inconvenient measure but gives the most battery life.
3- keep brightness about half or less; eyes are more important than battery life though.
4- keep the computer clean by restarting it every few days.

In my usage, it's rare that I need to be off on battery power for more than an hour or two, so I just charge my battery up to 55% and it's enough for me.

If you have an LED backlit screen and an SSD or 5400 RPM drive, you could probably achieve better results than I can, although I think my seagate 7200.3 hard drive is not a power hungry drive.

In general, intense users who can navigate pretty quickly will use up their battery quicker than slower users, because such users are getting more things done.

 

Thank you
I read a lot of posts said that 7200 rpm HD will not consume power more than 5400 rpm one. It needs more power to rotate, but in return, it's done work faster. So power needed is nearly equal.

 

Do a clean install I suspect that you might have too much junk and unnecessary programs and services. Screen brightness and undervolting play an important role IMHO.