Here we go again! With the launch of the Windows 10 Creators Update and Edge 40 (EdgeHTML 15), Microsoft has released a new battery usage test that, naturally, trashes the company's competition. This new test shows that Edge uses less power than both Chrome 57 and Firefox 52, and is bound to draw a response from its competition, especially Google, who doesn't like it when Microsoft takes a jab at Chrome's efficiency. Welcome to the battery usage wars! The same thing happened last year, in June, when a similar test showcasing Edge's longer battery life was met with responses from both Google and Opera. Not giving up on its claims, Microsoft re-ran the test in September, also publishing the testing procedure on GitHub, with the release of BrowserEfficiencyTest, a Selenium WebDriver that automates common user browsing operations, such as looking through a Facebook feed, going through some emails, and browsing the news. The September test was done on clean Windows 10 Anniversary Update (build 14393.105) version, while the new test, performed this month, was run on three identical Surface Book laptops running Windows 10 Creator's Update (build 15063). CPU, GPU, and Wi-Fi antenna power consumption were measured using onboard Maxim chips and the Windows Performance Recorder. Below are the hardware and software specifications of the testing rig: OS and browser versions OS Windows 10 Pro 15063.0 Microsoft Edge Microsoft Edge 40.15063.0.0 Chrome Google Chrome 57.0.2987.133 (64-bit) Firefox Firefox 52.0.1 (32-bit) Hardware Processor i5-6300U @ 2.4GHz 2.5GHz Memory 8G Graphics Intel HD Graphics 520 Two different types of tests were performed until a latpop's fully-charged battery gave out. The first test measured normal browsing performance and the second ran a looped Vimeo fullscreen video. For each browser, a minimum of 16 iterations were recorded per test, and the average between all iterations reported. Unlike the September tests [1, 2], Opera wasn't included. Normal browsing performance test In the normal browsing performance test, Microsoft claims Edge used 31% less power than Chrome 57, and 44% less power than Firefox 52. Video performance test In the second test, Edge played this Vimeo video for 751 minutes (12:31:08), while Chrome lasted 557 minutes (9:17:03) and Firefox for only 424 minutes (7:04:19). That's a whopping three hours over Chrome. Of course, all these tests need to be taken with a grain of salt. When one of the participants runs these tests and comes on top, it's kind of hard to take them seriously. Nonetheless, it's always fun to see multi-billion dollar businesses taking jabs at each other's products, like that time when Microsoft claimed in a now-deleted tweet that Edge is the first and only browser to feature tab previews, only to be mocked by Opera and Vivaldi, both which featured tab previews for years.