Battery technology one department where smartphones have been advancing the slowest - there is no clever workaround for doing more with less battery capacity. Application and power optimizations can only get you so far.
We believe that the substantial battery capacity is the second most important reason people like "phablets" so much, right behind the big screen. Surprisingly, neither of these phones is a champ in the battery capacity department. The Nexus 6P has the most - 3,450mAh - while the other two have 3,000mAh batteries (you can blame the pursuit of thinness for this).
Samsung has a track record of squeezing out as many hours as possible by using a power-efficient chipset and clever software optimizations. The Galaxy Note5 is a champ, even without the biggest battery in the world.
The Nexus 6p benefits from the latest power efficiency software tweaks Google has come up with in Android 6.0. The Doze feature, in particular, helps standby time, but that hardly is of any use when you use your phone actively. That's one area that a bigger battery helps.
The LG V10 has a second screen to worry about, too, so we tested its battery endurance twice - first, with the screen off, and secondly, with the screen on.
Battery life takes a noticeable hit when the secondary screen is active, which hurts its already average score, the lowest among the three smartphones by some measure.
The Samsung Galaxy Note5 will last the longest between charges, you can easily get three days with moderate usage. Even heavy users will struggle to deplete the battery in a day, the Note5 wins all three categories, often by a distinctive margin.
The Huawei Nexus 6P indeed has excellent standby performance, it's as good as the Samsung's. But the gap quickly widens when you push the smartphone - the browser and the video player especially will deplete the battery faster.
The LG V10 has an average endurance rating, not great for a flagship. The individual tests are not that bad; it's the poor standby performance that has the biggest negative effect. The talk time is not so hot as with the other phones either. Note that LG promises better battery performance out of its international model when network connectivity is involved (we tested the South Korean one).
Draining the battery is one thing, but topping it up is important too, and we're talking charging speed in particular.
The Galaxy Note5 comes with an Adaptive Fast Charger (Quick Charge 2.0), which puts out 9V at 1.67A. It charges up fully in 100 minutes (according to official numbers), but you can get 50% in just 30 minutes.
The Note5 has fast wireless charging capabilities as well, but Samsung must have thought that wires are old news and when wireless charging can bring the Note5 battery to full capacity in only 120 minutes - almost as fast as the wired charger! The phone supports both Qi and PMA wireless charging standards.
The LG V10 also comes with a Quick Charge 2.0 power plug, but the company is more conservative and promises a 50% charge in 40 minutes. Wireless charging is available as well but requires a special back cover.
The Huawei Nexus 6P is the only one of the trio to use the new USB Type-C standard. Its charger can put out 5V @ 3A, resulting in a max power of 15W. This one doesn't have wireless charging at all unlike previous Nexus models.
Winner: Samsung Galaxy Note5. With a long-lasting battery and varied fast-charging methods (both wired and wireless), the Note5 is a clear winner here.
Runner-up: Huawei Nexus 6P. While it won't last as long as the Note5 under heavy load (and lacks wireless charging), the Nexus 6P leads the LG phone in the most important department and that's power autonomy.
Third place: LG V10. The endurance of the V10 is fairly average in general, disappointing for a flagship. The always-on secondary display is a novel feature, but we're les