Some of the Best Battery Life on Android Today Comes on a Budget

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In our recent review of the Xiaomi Redmi Note 3 Snapdragon 650 variant, we noted some stellar battery performance. This was no ordinary 8hr-SOT battery life, this was legitimately 14+ hours of screen on time under working scenarios.

We asked our followers on Twitter which phone this screenshot originated from, and just one person could guess it correctly.



Most of the replies that originated on the tweet either were for phones that boast of massive 5,000 mAh batteries and above, or for recent flagships. This got us thinking, can current flagships really power through 2 days of use? Can you actually use a flagship which does not have you looking at the battery levels after every half hour of work and play? Or is battery life an area where mediocrity from flagships is acceptable, if not the norm?

One of the most defining features of battery life usually starts off with the actual battery capacity itself. This is by no means the only defining factor of good battery life, but it definitely is a good starting point. The energy stored in your battery is what powers the device. So if you have a larger reserve in terms of quantity, you’ll be able to use your phone for longer and less conservatively. With all other variables being equal, a phone with 3,000 mAh of battery would outperform a phone with 2,000 mAh of battery when it comes to powering through the day.

But is battery capacity the truest mark of battery life? Will having a bigger battery give you better battery life? The answer to this question is two-folds — on a very general scale, looking at general trends, this statement is true. But battery life is not only a function of battery capacity, but also of battery usage. This is something we saw back in 2013, with the Motorola Moto G managing to impress many with its battery life despite having a small 2,070 mAh battery. This starter phone came close to matching some battery behemoths of its time, like the flagship LG G2 with its 3,000 mAh battery. So it is true that sheer capacity is not the absolute determining factor by which we can judge a phone’s battery life.

Another one of the factors defining the battery life of a device relates to the screen. There are a few variables at play here: the screen size matters, so does the resolution, and the screen type as well. Along with the screen tech and the spectrum of brightness of the device, these factors influence how quickly the battery drains. A big 6″ QHD LCD display with above average maximum brightness may look very good with good color reproduction and adequate saturation, but it will certainly not be the battery’s best friend. The longer such a display remains on, the quicker the charge in the battery will be consumed up. Because of this, a lot of users tend to take Screen On Time as a defining character when measuring battery life — how long can the phone survive with its screen on under the users normal usage? Using SOT as a measurement tool without proper context is a flawed approach to measure battery life, but this is a topic for a different day.

Low and mid end phones with their mediocre screen tech see a trade-off as they bring lower resolution, but typically also last-generation screen technology. But are these all there is to it?

A factor that is often overlooked when talking about battery life is the SoC in use in the phone. Modern day flagship SoCs are built for speed, and in despite alleged optimizations, in 2015 many disproportionately traded battery efficiency in processing for raw power. A good example of this is the Exynos 7420, which is a good flagship grade SoC employed in the Samsung Galaxy S6 and the Note 5. Throughout 2015 we saw widespread adoption of the big.LITTLE setup with A57 and A53 cores. The A57 cores did the heavy lifting, yet employing A53’s tends to be a big trade-off with performance, but the battery efficiency that these cores offer remains unrivaled.

You only have to take a look at some good “real world” battery devices in the past few months to see the trend. The Huawei honor 5X is a good example, a device that stands no chance in competing against flagships but does not fail in the battery department, often delivering 6 hours of screen on time on our unit. The big.LITTLE setup on the Snapdragon 616 employs Cortex-A53 for both of the clusters, so it comes as no surprise that the phone can last as long as it can. The phone is certainly not the best at battery benchmarks either, but for a normal consumer, the phone can suffice all of his daily needs in both performance and battery life.

We can also see this in a lot of different SoCs and devices which employ the Cortex-A53’s. They tend to be poor in performance in synthetic benchmarks, but chug along fine in real world usage, often despite the burden of heavy and bloaty UIs popular amongst Chinese OEMs. Android’s idle time situation has been generally improving with every iteration as a whole, but major beneficiaries of these improvements are devices employing power-efficient cores, including those using them in dedicated clusters. Battery life in the low end continues to be one of the better selling points of these devices, being that one area where they can give flagships a run for their money.

So those of us who do seek battery life over cutting-edge performance, are we condemned to being restricted to low and mid end devices? Not necessarily. As spec wars thin out over segments such as SoCs, Screens, Memory and from factors, it is only natural for OEMs to shift their attention on towards battery capacity and efficiency. Until we get a true flagship phone with unnatural battery life, we may have to be content with sticking with low and mid end devices for the foreseeable future. But seeing how the low and mid end sections of the Android market is evolving in terms of hardware and software, and with the difference between two extreme points of the market (flagships v/s low end), this may not be a bad thing after all.

What are your thoughts on battery efficiency? Should flagships only be flagships for pure performance, or should they be flagships in areas such as battery as well? Let us know your thoughts in the comments below!