Aku does not keep promises BRAUN

So against my old Braun shaver (Series 2) This device is a milestone, particularly with regard to the intensity of the shave. However, the manufacturer's instructions with regard to the Aku-term (until 45 minutes) quite excessive in my opinion. While I can shave well, including hackles, but more than 17 to 20 minutes brings the Aku not unfortunately. Then the shaver will switch on the red LED flashing and stop after another 2 - 3 minutes.
Because I need a rule about 10 to 12 minutes for a clean shave, so I can not even shave twice myself with a full Akuladung. Very disappointing.
Otherwise: fits comfortably in your hand and the movement of the shaving head is optimal.