Sonicare Power

I got a new brush head for my sonicare toothbrush. This thing rattles my skull when the battery has a full charge. They must have done something radically different with the placement of the magnets or something else in the design of the head because the base I'm using has never been able to rock my head like this does. I can tell if the battery's wearing out because it feels normal. That extra power makes my teeth feel cleaner too.