https://www.zdnet.com/article/iphon...r-out-the-battery-faster-than-cable-charging/ In the comment section someone posted his opinion as an Engineer: "The things about wireless charging that do affect battery life? Excess heat, and excess top off cycles. Charging a battery produces heat, and inductive charging adds it's own heat to the process. Lithium cells don't like excess heat, and it shortens their lifespan. The excess top off cycles are a result of wireless charging being convenient: "Hey, here's a pad! Why not top off?"... even if it's for the 10th time that day. So what's the problem with that? Normal battery voltage for these cells is 3.7 volts. Topping it off pushes it up to 4.25 volts for most Androids, 4.28 volts for iPhones. Keeping the battery voltage that high all the time reduces the battery lifespan. Leaving the phone on the charging pad (or plugged in) overnight also causes the phone to cycle though charge/drain/charge cycles through the night. It will not damage the battery, but the cycling does flow more power through the cell, and that does affect battery life span. It's ok once in a while, but it's not something you want to do EVERY night."