LG G2 and MSM8974 Snapdragon 800 - Mini Review

Battery Life

One of the things Qualcomm promised would come with Snapdragon 800 (8974) (and by extension the process improvement with 28nm HPM) was lower power consumption, especially versus Snapdragon 600 (8064). There are improvements throughout the overall Snapdragon 800 platform which help as well, newer PMIC (PM8941) and that newer modem block onboard as well, but overall platform power goes down in the lower performance states for Snapdragon 800. In addition the G2 has a few unique power saving features of its own, including display GRAM (Graphics RAM) which enables the equivalent of panel self refresh for the display. When the display is static, the G2 can run parts of the display subsystem and AP off and save power, which they purport increases the mixed use battery life case by 10 percent overall, and 26 percent compared to the actively refreshing display equivalent. In addition the G2 has a fairly sizable 3000 mAh 3.8V (11.4 watt-hour) battery which is stacked to get the most out of the rounded shape of the device, and utilizes LG's new SiO+ anode for increased energy density compared to the conventional graphite anode. 

Our battery life test is unchanged, we calibrate the display to exactly 200 nits and run it through a controlled workload consisting of a dozen or so popular pages and articles with pauses in between until the device dies. This is repeated on cellular and WiFi, in this case since we have an international model of the G2 that lacks the LTE bands used in the USA, that's 3G WCDMA on AT&T's Band 2 network. I've tested 3G battery life on devices concurrently for a while now in addition to LTE though, so we still have some meaningful comparisons. The most interesting comparisons are to the Optimus G (APQ8064) and HTC One (APQ8064T) previous generation.

The LG G2 battery life is shockingly good through our tests, and in subjective use. The combination of larger battery, GRAM for panel self refresh, new HK-MG process, and changes to the architecture dramatically improve things for the G2 over the Optimus G. While running the two web browsing tests I suspected that the G2 might be my first phone call test to break 24 hours, while it doesn't break it it comes tantalizingly close at 23.5 hours. I'm very impressed with the G2 battery life.

The G2 also charges very fast for its battery size. I've been profiling charging behavior and current for devices for a while now, since I strongly believe that battery life and charging speed are complementary problems. You should always opportunistically charge your smartphone, being able to draw as much while you have access to a power outlet is critical. The G2 can negotiate a 2A charge rate on my downstream charge port controller and charges very fast in that mode. Of course the PM8941 PMIC also includes some new features that Qualcomm has given QuickCharge 2.0 branding.