GTrusted

The iPhone 6s comes with a simple Apple 5W USB Power Adapter (5 volts @ 1 amps) charger.  It's interesting to see the charger send charging pulses to more efficiently charge the phone and reduces the current to .78-.80 amps and again down to about .62-.64 amps before finally steadily reducing its current when the battery is close to 100%.

Total charging time is about 2 hours with power starting at 4.8 watts and eventually dropping down to 1.2 watts.

This charging behavior is much different from the smoother more continuous charging seen with the iPhone 7 and the same Apple 5W USB Power Adapter as seen in this review.