Modern smartphones pack the power of a high-end PC into devices that fit in your pocket. But despite impressive improvements in processors and displays, one constant has been weak battery life.
In his 2015 book The Powerhouse, journalist Steve LeVine describes a battery race characterized by intense competition and corporate espionage. But the world’s first super battery still hasn’t materialized.
Samsung Galaxy S9
The Galaxy S9 is a fine phone, but it feels like Samsung could have done more. It ticks all the right boxes for most buyers: a gorgeous design, a stunning screen and plenty of cool new features to play with.
But it’s not clear that the new Galaxy S9 is any better than last year’s model at handling long days of use. In our battery drain test, the Exynos version of the S9 averaged a run time of 15 hours, 20 minutes — about the same as the previous Galaxy S8. This result includes a full day of light usage, including checking messages, pinging the web and doing some social media swiping.
When we ran more intensive tests, the S9’s performance suffered a bit. The Snapdragon 845-equipped Galaxy S9 Plus lasted longer in these tests, but still fell short of last year’s Galaxy S8’s 16-hour run time.
There are a couple of reasons for this. One is that the Exynos 9810 S9 has a slower CPU clock speed than the earlier model’s. This makes the cores less efficient and uses more power. Samsung’s own battery optimisation settings also throttle the M3 cores down to 1469 MHz and change some scheduler settings that make it more conservative in its power usage. This helps to restore peak performance to the level of the old Exynos S8, but it takes away from UI responsiveness and slows down video playback.
LG G7
LG’s flagship smartphones usually fall well below the category average in our battery tests. With a 3,300mAh battery, the G7 ThinQ has the potential to go hours longer than last year’s model, but it fell short in our latest test. The phone lasted 8 hours and 35 minutes during continuous web-surfing over 4G LTE on T-Mobile’s network, while rival phones from Apple, Samsung and Google clocked in at more than 10 hours.
This year’s phone uses a new chipset and screen, so its performance should have been much better. It’s unclear why it wasn’t.
The G7’s 3,000mAh battery has enough capacity to comfortably last through a full day of moderate use, but most owners will still need to charge it overnight. Fortunately, this year’s phone is also rated IP68, so you can dunk it in 1 meter (about 3 feet) of water for 30 minutes without damaging the internal components.
The G7’s other notable features include a headphone jack and a fingerprint sensor that doubles as a power button on the right edge. It runs Android 8.0 Oreo and will get the upgrade to Android P later this year. The phone comes in a few colors, including platinum gray, Aurora black and Moroccan blue. The display is bright and offers accurate colors, though it has a slightly blueish tint when you enable the Comfort View mode.
Apple iPhone X
The $999 iPhone X packs a Li-Ion 2716 mAh non-removable battery that gives the phone decent stamina. The phone has a power efficient OLED display and a fast capable processor that keeps it running all day without much need to charge.
Apple’s iPhone X managed to run for 12 and a half hours in our benchmark test. This gave it a decent lead over the iPhone 8 Plus, although it still fell short of my Pixel 2 XL’s 13 and a half hours.
Like all smartphones, the iPhone X is going to age over time, and its performance is likely to decline gradually. But Apple’s software is designed to prevent it from getting sluggish, as has been seen on Android phones, by slowing down the device as battery health declines.
The iPhone X is also the first iPhone to support wireless charging, making it compatible with a wide range of pads. This will keep it powered up for longer, and is a major advantage over the older iPhones that require you to buy an expensive third-party charger. For these reasons, the iPhone X is the best refurbished iPhone to buy. Swappie’s reconditioned iPhones have consistently ranked above their Android counterparts in both battery and performance tests. They also retain their strength and efficiency longer than most refurbished phones, making them ideal for those who need a reliable smartphone that can last all day without needing a power bank.
Huawei P20
The P20 is Huawei’s latest effort to get a foothold in the premium smartphone market. Its incredibly impressive camera setup, which is the best triple-lens phone camera that DxO Mark has ever tested, helps this smartphone stand out in a very crowded field.
Those Leica lenses on the back of the P20 are complemented by a neural processing unit on the Kirin chipset, which adds AI capabilities to the smartphone’s cameras. This allows the P20 to identify objects, suggest shooting modes, and even create a shallow depth of field for selfies.
On our battery test, the Huawei P20 lasted over 39 hours without activating power saving mode. That’s enough to last you through a full workday, though you might need to recharge it before heading out for dinner or drinks with friends.
Like the S9, S9 Plus and iPhone X, the P20 is powered by a HiSilicon Kirin 970 octo-core CPU (four 1.8GHz Cortex A53s and four 2.3GHz Cortex A73s). It scored 1,893 on the single-core Geekbench benchmark and 6,736 on multi-core, which puts it in the same class as the S9.
Like all of the smartphones we’ve reviewed here, the P20 has a 5.8-inch 2240×1080 AMOLED display with an 18.7:9 aspect ratio. Its pixel density is only slightly higher than the Samsung Galaxy S9’s and Apple iPhone X’s, but it has better contrast and color accuracy. The fingerprint sensor doubles as a gesture-based navigation button, which can free up screen real estate by allowing you to skip the Android Home/Back and Recent buttons.