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traldan
What's DOS?
Posts: 2
Registered: ‎09-19-2008
Location: Virginia
Views: 7,033
Message 1 of 9

Lenovo T400 9-Cell Battery Life?

I have a brand-new T400 (as of about 2 weeks ago) with a 9cell battery.  It has a P8600, 2gb RAM (1 DIMM), Intel Wireless 5300, Bluetooth, 160 gig 7200 rpm hard drive, etc.

 

Perhaps I expected too much, but as of now, my battery life seems rather poor considering the "brand new Centrino 2" with "improved battery life".  In Windows Vista, with wireless on, bluetooth off, and the screen brightness set between 25 and 50%, I'm lucky to break 6.5 hours.  In Ubuntu, with wireless on, bluetooth off, and the screen brightness set between 25 and 50%, I'm lucky to break 2.5 hours.  Neither of those figures is particularly impressive, I feel (perhaps I had improper expectations), especially considering I'm lugging around a 9 cell battery.

 

Are my expectations wrong, or is my battery/hardware fubar?

zachman123
SCSI Port
Posts: 56
Registered: ‎08-12-2008
Location: Michigan
Views: 7,007
Message 2 of 9

Re: Lenovo T400 9-Cell Battery Life?

I have the exact same config (from what you've described).

 

My 9 cell gave me about 8 hours the first time on max. battery life, but now is only estimating 3 the second charge around.  In addition, my new 4-cell only lasted 1:30 on max battery life.  Why the sudden drop (what's causing my laptop to suck more power?).  I've calibrated/reset the 9-cell once already.

Any ideas?

 

edit: RMClock shows an estimate of 28800mW being used.  This is with wifi on, 35% screen brightness, just browsing the web.  Seems pretty high.

Message Edited by zachman123 on 09-22-2008 10:25 AM
zachman123
SCSI Port
Posts: 56
Registered: ‎08-12-2008
Location: Michigan
Views: 6,960
Message 3 of 9

Re: Lenovo T400 9-Cell Battery Life?

I think it was that my switchable graphics stopped working.  It said it was on Energy Saving, but wouldn't switch at all, and the ATI card still showed up in device manager.  Reinstalled the graphics driver, and now my est. discharge rate is down to 12471mW.  Much better.

 

I just wish there was another program besides Lenovo Power Manager that could switch the graphics.

Message Edited by zachman123 on 09-22-2008 01:52 PM
george99
Punch Card
Posts: 59
Registered: ‎09-04-2008
Location: FL
Views: 6,937
Message 4 of 9

Re: Lenovo T400 9-Cell Battery Life?

There is another program to switch the graphics.

The ATI software included with the T400 has the ability.  However, it seems like Lenovo disabled it.

 

When I was trying to figure out how to swtich graphic cards, I assumed that it would be in the ATI software, and not strictly by left clicking the battery icon.

Anyway, I went to the help file for ATI and searched for switchable graphics, and it said that there should be a specific button in the ATI software that allows you to make the switch.  However, it isn't there.  So I am guessing that Lenovo disabled it.

 

I bet someone here can find a registry hack to restore it.

traldan
What's DOS?
Posts: 2
Registered: ‎09-19-2008
Location: Virginia
Views: 6,935
Message 5 of 9

Re: Lenovo T400 9-Cell Battery Life?

I even have integrated graphics enabled in Vista, thats what the 6.5 hours came from.  It wasn't a huge difference in battery life from discrete to integrated.
ClickRight
Fanfold Paper
Posts: 10
Registered: ‎09-23-2008
Location: CA
Views: 6,845
Message 6 of 9

Re: Lenovo T400 9-Cell Battery Life?

My T400 with 9 cell battery also has poor battery life, only managing to squeeze 6 - 6.5 hours of the battery when using the integrated graphics. Anybody know if Lenovo had a bad batch of batteries or something? I'm thinking about calling and asking for a replacement.
zachman123
SCSI Port
Posts: 56
Registered: ‎08-12-2008
Location: Michigan
Views: 6,721
Message 7 of 9

Re: Lenovo T400 9-Cell Battery Life?

I don't think it's the batteries... take a look at in power manager at how many watts your T400 is using.  Ideally, it should be down to 8-9W (read as 8000-9000mW)at 40% brightness, wifi on, idle, web surfing etc.  However, most people (including me) seem to be getting more, around 11-14.  This results in lower battery life as the computer is using more power.

 

Also, make sure your switchable graphics is working (or turn it off in the bios to integrated).  Mine decided to bug out once, turning on the ati card but saying it was in integrated.

ClickRight
Fanfold Paper
Posts: 10
Registered: ‎09-23-2008
Location: CA
Views: 6,556
Message 8 of 9

Re: Lenovo T400 9-Cell Battery Life?

Sorry, zachman123, I wasn't able to find the power usage in the Lnovo Power Manager. I am using the advanced view and looked through all the tabs. Is there a 3rd party program that can tell me this information?
zachman123
SCSI Port
Posts: 56
Registered: ‎08-12-2008
Location: Michigan
Views: 6,517
Message 9 of 9

Re: Lenovo T400 9-Cell Battery Life?

For a while this morning my wattage was up at 28 watts!  I have no real idea why, but I still think it might have to do with graphics drivers.  I thik it sometimes forgets to turn off the ATI card and for some reason consumes a crazy amount of power.  By the time I figure out how quickly my battery gauge is dropping, I've already lost a lot of battery time.

 

I think I'll try going to integrated only in the bios and see if that fixes it for now.

 

ps you can use RMClock to show your battery stats as well as tune down your cpu power states and such... I don't know why the battery info shows up in Lenovo Power Manager for me now.

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