The first big surprise: this charger is big and imposing enough! The picture does not give that impression. Then there was some net time fan noise, so as not to close to your head at night for example.
Charging time: I wonder if, really, the batteries are fully charged after 15 minutes. Time will tell me. I have several brands of rechargeable batteries and they are not all equal before the charging time! A so use with batteries Duracell.