As for battery life, I was actually very impressed with what the combination of a 35 Wh internal battery and Intel’s Core M CPU delivered. The ThinkPad Helix lasted noticeably longer than the Yoga 3 Pro during my standard use of the device, which is a good result considering the Helix’s battery and display are 22% and 24% smaller respectively. When writing Word documents, editing Excel spreadsheets and browsing the web in Chrome, I achieved around seven to eight hours of battery life with the display set to a moderate brightness level. This is a good result; it’s around what I would expect for this sort of device, and matches Lenovo’s battery life estimates. The original model was rated for six hours of life, and had a 20% larger (42 Wh) battery, which is a great result for the efficiency of Intel’s Core M chip.
As you can see from the battery results above, Core M fares a lot better in the ThinkPad Helix than the Yoga 3 Pro. In video playback, the Helix lasted as long as a super low power Bay Trail 8-inch tablet, while in Wi-Fi it lasted an admirable six hours. I also recorded a quite decent result in an intense use benchmark: playing Crysis 3 at 100% screen brightness. Here, the Helix lasted two and a half hours, which was more than double the length of the Alienware 13. Granted the Alienware is a gaming machine with more powerful hardware, but I thought the Helix would fare worse than it did. If you opt for the Ultrabook Pro Keyboard, you’ll get an extra 26 Wh battery (7% smaller than the original Helix’s keyboard dock). This battery will allegedly extend the total system battery life by four hours to a total of 12, though as I didn’t have time with it, I can’t verify those claims.
