IPS: Bad for battery life?

[mfeller2]

The recent Anandtech article on IPS monitors shows active power consumption to be substantially higher vs. normal LCD monitors.

Translating this to a laptop purchase that I am considering: there is a trade-off of IPS vs battery life. Is this right?

(Thinkpad X220 has an IPS option)

 

[nipplefish]

I'm planning on buying an x220 this week, so I looked into this, and here's what I found:

the x220's IPS panel is built by LG, and apparently their "Enhanced IPS" technology allows for fewer backlights and thus lower power draw. I think the difference will be negligible... nobody has ever mentioned it in any of the reviews I've read.

IPS LCD panels require a bit more in terms of light source (CCFL lamps) to achieve a certain level of brightness. In other words, IPS LCD panels have a slightly lower aperture ratio. What LG Display did was improve the structure of the TFT (thin-film transistor) to enhance the aperture ratio. And that in turn means that in order to achieve the same brightness level you can do with less CCFL lamps.

http://www.displayblog.com/2009/02/13/lg-display-e-ips-lcd-panel-update-2/

And also from Wikipedia:

Wider aperture for light transmission, enabling the use of lower-power, cheaper backlights. Improves diagonal viewing angle and further reduce response time to 5ms.

http://en.wikipedia.org/wiki/TFT_LCD#In-plane_switching_.28IPS.29

 

[nataku00]

I have an x220i (i3 proc) with the premium screen (IPS) and I own both the 4 cell and a 9 cell battery for it. I did not install the Lenovo power management software so the estimated times for each battery is via win7's built in monitor. With the 4 cell, high performance setting in win7 power management, and at maximum brightness, the estimated battery life with no applications open is ~2 hrs. With the 9 cell battery installed, under the same settings, it estimates ~9-10 hrs.