Battery Life And Charging
As mentioned, Shield was originally specified for 38 Wh of energy and later revised down to 28.8 Wh. Of course that roughly 25% reduction is going to chip away at the console’s run time in games and movies. But it also helps keep weight down.
Nvidia estimates that one charge should yield four to five hours of play time in the most demanding Tegra 4-optimized titles, while more typical Android games might run for as long as 10 hours.
We fired up Epic Citadel, which isn’t specifically written to tax Tegra 4, but still offers a High Quality setting we can use on all of our comparison devices. With Wi-Fi enabled, our display calibrated to 200 nits, and the walk-through looping, Shield ran for six hours and thirty-nine minutes. Do the math, and Nvidia’s platform is averaging 4.33 W of power consumption in a demanding 3D workload.
Going back the other way, we connected the 2 A charger that Nvidia bundles with Shield, which the company says provides the best charge time and performance. Charging a completely drained to a full battery took four hours and 56 minutes.
A second drain test measured how long it'd take to deplete Shield's battery if all you do is stream PC games to the device. Because this is a video decode workload, you get a lot more run time than the 3D benchmark, despite constant Wi-Fi traffic. Streaming Skyrim in the same room as our router, we managed to get nine hours and 58 minutes from Shield. I cannot imagine any situation where you'd want to be staring at that screen for 10 hours without a break to eat, call your mother, or charge Shield back up. That's pretty safely all-day gaming battery life.