Introduction

Smartphone batteries piggybacked on the growing screen size to go up in capacity to support both the screen and faster chipsets. Slower to deplete, the new batteries also proved slower to charge so manufacturers tackled the issue with new standards.

USB 2.0, the most popular charger at the moment typically puts out 500mA. Gradually manufacturers started bundling more powerful chargers, going over 2A in some cases. USB 3.0 offers a bit more power than the older standard, but its wide adoption in smartphones is not happening anytime soon.

Both manufacturers and chipset makers were not content with this and developed their own standards. We'll be testing solutions from Qualcomm, Oppo, Samsung and Intel (the last two seem to use Qualcomm's tech). We also have two iPhones in the mix even though Apple doesn't have an official fast charge solution.

There's a common standard on the horizon too - while USB 3.0 failed to take hold on mobiles, the USB Type-C connector might prove more successful. Reversible and capable of carrying more power - up to 3A at 5V for 15W total it looks to have what it takes. It's still larger than 2.0 connectors though, so we'll see if it will play nice with the ongoing struggle to make smartphones as slim as possible.

This matches the power from the Quick Charge 2.0 standard, though the latest USB standard also has an optional Power Delivery profile that can push up to 100W. That's intended for laptops and monitors, but the profile also has a number of lower steps which may one day land on phones and tablets.

We may or may not see USB Type-C mobiles this year, but it's clear that the current chargers will survive. Some of them fundamentally change the battery, Oppo for example splits it into multiple cells that are charged separately.

Since these charging standards work best when the battery is close to empty, we started with a fully depleted battery and wrote down the charge every five minutes. The phones were off initially and we powered them on after the first five minutes.

We'll compare all the phones together, but we'll also cover each phone's performance individually.

If you're new to charging tech, we researched each one we are testing and summarized our findings on the next page. You can quickly get acquainted or skim it and go to the following page for the showdown.