MojoKid writes: Mobile workstation notebooks typically offer a fair degree of performance but usually at the expense of battery life. It comes with the territory for machines that are configured with higher-end processors with discrete graphics chips, as well as high-end displays that take more power to light up. Lenovo, however, seems to have found a way to strike a better balance with their new ThinkPad W550s, which comes equipped with an Intel Core i7-5600U CPU, an NVIDIA Quadro K620M GPU, and a 15.5 inch IPS display that sports 2880X1620 native resolution. With that kind of horsepower and that many pixels to push, you would think untethered up-time wouldn't be its strong suit but Lenovo configured a snap-in extended battery for the W550s. The 6-cell extended battery, in combination with its 3-cell internal battery, was able to power the machine for over 18 hours of light-duty web browsing in real-world testing (Lenovo claims up to 20 hrs of battery life). The machine also lasted over five hours under heavy-load Battery Eater testing, and the extended battery is unobtrusive, tilting the keyboard up slightly toward the user but keeping well inside the machine's footprint.