Delete comment from: Ken Shirriff's blog
I agree that noisy, spiky output can lead to instability and undesirable behaviour in sensitive electronics, such as the aforementioned touch-screens, while charging... but a battery isn't as picky! I'm not talking about extended voltage surges (which will overheat a battery or trigger a protection circuit), or insufficient voltage/current which simply increases charge time (but doesn't cause harm). Batteries will happily accept any electrons that come by. In fact, a battery should act as a great big smoothing capacitor.
I'm not defending the junky Chinese chargers that might zap you, burn your house down, or simply don't work, but lets not get carried away and pretend like we're performing high precision experiments in a research lab. Most of us just want to charge a device, and you don't need to shell out a day's wages for a shiny crApple branded premium charger to get the job done.
I still have an adapter from a Pong game console. It consists of a transformer, a single diode and an electrolytic capacitor.
Jan 19, 2013, 8:43:24 PM
Posted to A dozen USB chargers in the lab: Apple is very good, but not quite the best