Which lenovo laptop has the best battery life?

I've read the T440 battery is good and lenovo claims 12 hours but after reading reviews i saw that people are only getting 4 hours


I need a laptop with at least 8 hour battery life

 

On my t440s with touchscreen and the 6-cell battery, 12 hours is definitely achievable with a light load and power saving mode enabled.

 

Are you sure a 4 hour battery life is not caused by that particular device being defective or specific high load scenarios?

From what I have seen from the reviews, they have generally praised the device battery life.

 

Did those reviews state under what conditions they ran the laptop under? Generally when battery life is advertised, it's done so assuming a conservative power plan is being used. Maxing screen brightness, using Wi-Fi, and especially using demanding programs will cut down the 12 hours significantly.

 

don't waste your time reading reviews about battery life, they are all very skewed, especially the ones on lenovo, every laptop i get from lenovo seems to have a very poor quality battery, it works good for a 2 months, then it starts to go downhill rapidly, not sure, i am very religious about taking care of my laptops

in my opinion, just looking at the specifications of hardware, the x series would produce the best battery life, screen is the main cause of the depletion of battery life

 

The X240 has by far the best battery life. It will last you a realistic 16h while surfing with the 3c+6c Battery. (95Wh) However, only non-touch HD models last that long.

Not really, that is only the case with very few laptops. Most of the power is used by the CPU. However, as CPU's are becoming increasingly power efficient, the power used by the screen may become more apparent, as can be seen on the X240. (where the FHD touch models don't last as long as the basic configurations)

 

Nope.

The idle power consumption of an X240 is between 4W - 7W. (According to measurements made by Notebookcheck.) The LG LP125WF2 (FHD,IPS) panel commonly used in the X240 has a typical power consumption of 5W, according to it's datasheet.

As you can see, MOST of the power consumption is due to the screen. The HD version of this panel also has similar ratings - as the majority of consumption is due to the backlight. Remember that Haswell processors are very efficient in their low-power state.

Also, fun fact: IPS screens consume 10-15% more power than TN screens do. (According to Wiki)

 

That is incorrect. The X240 panel uses 5W at maximum brightness, which is not something most people use all of the time. 50% seems a lot more sensible. The second mistake is that you are assuming idle conditons. Now I don't know about you, but most people I know actually do something when they use their computer, and while current CPU's are very power efficient at idle, the constant wake ups caused even by simply moving the mouse pointer make it impossible for the CPU to be at idle 100% of the time. While browsing the web, the CPU has multiple bursts in which a lot of power is consumed. However, there are of course moments of idle in which power consumption is low. The average of that results in your actual power consumption.

Nevertheless, what I was acutally referring to was the absolute maximum power consumption that is theoretically possible and it is obvious that a current Haswell CPU can use much more than 5W of power.

 

Source please?

Disagree. Most people who use this laptop for work, usually are working in a brightly lit office-type environment. Most people also have their brightness usually set at 75% or more, otherwise you simply cannot read/see anything.

True, I am. Though idle time is a lot more significant than you think.

And I don't know what planet you live on, but I have worked in many offices, and if you take a look around at your colleagues/other people, people actually do spend a lot of time reading, yes.

 

Test Lenovo ThinkPad X240 Ultrabook - Notebookcheck.com Tests

Notebookcheck tests power usage with minimum brightness, medium brightness (in this case 178 nits) and maximum brightness. Power usage of the system at min. brightness is 3.9W (idle), 6.2W at 178 nits (more than enough for well lit office enivronments) and 7.3W at max. brightness. The maximum power consumption of the display according to these measurements is about 3.4W, which is lower than the 4-5W that the old X220 IPS used to have. ( Test Lenovo ThinkPad X220 (IPS) Subnotebook - Notebookcheck.com Tests ) So there has been improvement in that regard. This X240 that was tested had the HD panel.

At 178 nits (more than enough) power usage of the panel is a mere 2.3W. I currently reside in a weird place called England, and while many strange things exist here, most people that I have enountered use their laptops at about 100-150 nits brightness,

The FHD model uses much more power: http://www.notebookcheck.com/Lenovo-ThinkPad-X240-Test-des-Full-HD-Modells.117185.0.html

Roughly 4W at about 150 nits. The maximum power usage is about 5.9W.

I never said it was insignificant. In fact, I was trying to explain how significant it really is, because of the big difference between idle and seemingly light tasks like surfing that cause these CPU bursts.