It’s time for some extreme testing. Seriously, skip to the summary if you just want to know if the Lenovo U300s has good, average or poor battery life. Stay with us if you want to learn more about how efficient this neat little Ultrabook is. We’ve completed a suite of tests here that we hope gives you an idea of how the battery life would work out for your use case.
In summary we were a little disappointed in the Lenovo U300s we have here. Background power usage is much higher than many other Ultrabooks and the screen requires a lot of power to make it bright enough to use. The U300S has a relatively large battery which helps to provide good battery life figures despite the so-so efficiency. Turbo seems to work well and cooling performance is good. The fan is there when needed but doesn’t give us any nasty surprises.
The Lenovo U300s comes with a 54.7Wh battery which is a good size in comparison to other Ultrabooks. The review model used for these tests is running the following setup:
- Core i7 2677M (800Mhz / 1.8Ghz / 2.9Ghz) CPU with 4GB RAM, 256GB SSD.
- Room temperature a warm 24 degrees Celsius
- BIOS 56CN43WW (Latest at time of writing)
- Latest energy management drivers from Lenovo (22nd May 2012)
- Battery wear of the test device – 6%
- Manufacture date 22 Feb 2012
- All power drain measurements taken through ‘Perfmon’ and the battery status discharge rate counter
By turning of the Wi-Fi, Bluetooth, turning on battery-saving mode (which locks the CPU at 800Mhz as with all 1st-gen Ultrabooks) turning off speakers and letting the Lenovo U300s settle down and turn the back-light off we got a reading which represents background drain. It’s often an indicator of how efficiently the motherboard and peripherals are designed. 78 ‘tasks’ were running as this test was made.
- Screen off idle – 4.5w (Samsung NP530 – 3.9W, Toshiba Z830 3.1W)
- Screen low idle – 5.6w
- Screen max idle – 8.0w
The results are surprisingly high here and the screen is taking a serious amount of juice at full power. Doing nothing on the Lenovo U300s could run the battery flat in under 7hrs. Given this high base level of power drain, there’s little scope for the Lenovo U300S to be the most efficient Ultrabook we’ve tested so far.
Local MP3 playback
Local MP3 playback using Windows Media Player
Screen Low – 7.7W
Screen off - 6.2W
These numbers are high and largely due to high background drain.
Streaming MP3 playback (Wi-Fi On)
With WiFi enabled and Groove Salad streaming through Windows Media Player the figures were as follows:
Screen Low – 7.8W
Screen off – 6.4W
Again, poor figures but showing at least that the Wi-Fi card is efficient. In the test the U300S was two walls (est. 12m) away from the hotspot.)
Running-up Chrome with 50% brightness (5/11) we went to work with three tabs. Tweetdeck and Gmail (including Google Talk active) and Google Plus should be referred to as applications as they are actively using resources all the time. Over a 20 minute period in low-power mode we were able work smoothly
Average drain was 9W which is better than expected (and good compared to mainstream laptops) but still below a lot of Ultrabooks. For example, we have measured the Toshiba Z830 at 7W average in this scenario.
Office Working – Webs and Apps, Music, Image editing
To emulate a more typical working environment we ran Windows Live Writer, set Media Player going, changed to ‘balanced’ performance profile and started writing an article and editing some images with Windows Live Gallery. Chrome was also running with 3 ‘apps’ in tabs. Gmail, Tweetdeck and Google Plus.
The 10-minute average power usage was 10.2W, again, not the best result for a 1st-gen Ultrabook
Noise heat negligible in ‘office working’ mode
After we turned the music off and we could just about hear the fan. It’s not loud and the system didn’t get warm at all across the keyboard. There’s a warmth on the bottom but nothing that would be uncomfortable on a lap.
Converting a video – 21W to 25W
A key feature of the Ultrabook is that the Intel Quick Sync subsystem is extremely efficient at converting videos. Assuming you use the correct software (it must support the Intel Media SDK), most of the hard work is done in fast, dedicated silicon which keeps CPU usage down.
We used Cyberlink MediaEspresso for this test. A 55 second 1080p file of about 30Mbps and a 720p WMV file were down-converted it to a 720p, 3Mbps video – the sort of thing you might do in order to transfer videos to portable players or upload to YouTube. The result was impressive. In performance mode the process of converting 1m30s of video took just 23 seconds and used a peak of 26W, an average of 21W. While the peak and average power usage might seem high, the duration of the effort was low. The higher clocked Core i7 CPU here potentially showing that it saves power over lower-clocked Core i5 or i7 components.
Pushing it too the limits.
With WiFi on, Bluetooth on, a USB stick inserted, screen at high brightness, high performance mode, battery eater pro and Cinebench running while listening to some music, the average drain was 33.2W with Turbo stable at 2.3Ghz. Fan noise was clear but only air noise. No mechanical noise can be heard. This is slightly better than average in terms of noise. Some warmth was building up near the exhaust port on the left hand side but acceptable and nowhere near as hot as the Dell XPS 13.
This is a very important feature to mention and in many ways lifts the U300s up above other Ultrabooks in terms of battery life and mobility. The Lenovo U300S can charge to 50% capacity in 30 minutes. (We assume when the device is not being used.) Being able to top-up this quickly is a feature you’ll never want to give up once you’ve used it. We hope that manufacturers can improve this fast-charge feature and implement it more widely.
And finally, to sleep – 4 days
In an 11.5 hours sleep test I saw the battery drain 9%. The text was actually only a 10hr sleep test with hibernation mode kicking in for the last 1.5hrs. 4 days sleep is a useful feature.
Full reviews – Lenovo U300S
We track and list reviews from around the web in our product database. The Lenovo U300s page is here.
Our hands-on overview is here. We also have a 4-way comparison including the Lenovo U300S here.
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Background system drain on the Lenovo U300s seems to be higher than most Ultrabooks but high-end usage reduces the effect of this. In addition, the Lenovo U300S has a good 54Wh battery which balances out some of the inefficiencies. In a fairly low-end office scenario with a clean system we saw what would equate to 5hrs worth of working time but we want to note that the screen brightness does need to be pushed up higher than many Ultrabooks and this affects battery life.
The U300S is relatively quiet and keeps cool under load. Thermal design seems very good, especially after seeing sustained Turbo Boost rates of 2.3Ghz under load.
We suspect there is a little more to be had from the U300s although it’s difficult to see where that might come from. The Windows build is free of any obvious crapware. Windows 8 may help. (We’ve seen drops in idle power usage in our tests on some other laptops and tablets.)
Overall, unless you’re an ‘efficiency’ fan you’re going to be happy with the U300S as it returns real-world battery life figures close to the average in the Ultrabook class.
These tests were done with a relatively fresh system build (as provided by Lenovo) and by a knowledgeable tester. Remember that a loaded system with many background process can easily push up the power drain. In addition to the effects of background applications, careful attention should always be given to screen backlight, WiFi hotspot and of course, connected peripherals. Connecting USB peripherals can be a big power drain. High environmental temperature can also increase battery drain rates.
Do you have a Lenovo U300s? How is the battery life for you?