According to Lenovo, the Yoga 900 comes with a four-cell 66 Whr battery that's supposed to last around 9 hours, for video playback. Our Battery Eater test is significantly more strenuous than just streaming HD video content, as it stresses the CPU, GPU, memory and even the storage subsystem. It's truly a worst-case test that is meant to see how long a device will last under much heavier workloads.
In this test we set screen brightness to 50% and leave WiFi enabled, while the test is running. Power is then removed from the system and in addition to the test script, we monitor the device for a final uptime score measured in minutes.
In our standard web browser-based test, which loops a site every few minutes with screen brightness set at 50%, the Yoga 900 mustered just under 7 hours. While not quite in line with the best-case-scenario mark of 9 hours that Lenovo claims, that's still a strong outing for a machine this thin.
Lasting just under 3 hours, the 2.85 pound Lenovo Yoga 900 and its Skylake-U Core i7 processor offer up respectable performance, once again in the top quadrant of our test group. Frankly, however, this test doesn't really allow the ultra-low power state characteristics of Intel's Skylake-U platform to kick in, rather it just pushes on system resources until the battery begs for mercy.