Here’s how the tests were performed:
To test each handset, we ran it down until it was powered off. Then, we charged each device back up to 5 percent. This put all of the phones on an even playing field, as some don’t power down until the battery is completely dead and others cut out when there’s still 3 percent or more battery remaining. Once each phone had reached 5-percent battery life, we plugged them in and started the clock. We then noted the charge of the battery at 5 minutes, 15 minutes and 30 minutes. Finally, we noted how long it took to charge the battery, first to 80 percent and then to 100 percent.
The Asus Zenfone 2 led the pack initially charging to 17% in 5 minutes, 32% in 15 minutes, and 53% in 30 minutes. Compare that to the iPhone at 6% in 5 minutes, 20% in 15 minutes, and 36% in 30 minutes.
Examining the time it takes to reach 80% and 100%, the Galaxy S6 comes out on top reaching 80% in 48 minutes and 100% charge in 1 hour and 22 minutes. The iPhone 6 comes in at the bottom of pack taking 1 hour and 15 minutes to reach 80% and a lengthy 2 hours and 35 minutes to reach 100%.
[Source]
