Iphone Voltage Input

Richierich77 wrote:

When I am charging my iphone 15 Pro at 50% does the Voltage increase and then decrease as it gets closer to 100%

If you fast charge with an Apple (or other) USB-C PD power source of 20 watts or higher the voltage starts at 9 volts, then drops to 5 volts when the fast charge portion of the charge cycle finishes around 80%.

No. The Voltage is constant.

What may change is the rate of charge, how much energy the iPhone pulls of any, which is not related to the voltage. Voltage is always 5 Volts.

If you are concerned about overcharging it, don't be. The iPhone will handle its charging, and cannot be overcharged.

click here ➜ About Optimized Battery Charging on your iPhone - Apple Support