Outdated technology, otherwise good

This model I have already bought a third time, alone because each time the battery after 2-3 years as strong subsides that one thus can no longer travel without charging cable and the sense of a wireless toothbrush thereby lost. Besides the fact that my toothbrush after 3-4 days currently is empty (new model = 10 days at 2x brushing / day), the battery requires up to 15 hours until it is loaded and loses after 2x brushing noticeably performance.

I can connect several speakers who criticize the outdated technology. Here it must be urgently overhauled to meet the demands of customers and to be able to say that you served the premium segment. Only the sensational slim, pleasing and well-to-grip design and good brushes are Premium.

To be improved would be:
- Lithium-ion batteries installed
- Constant speed control
- Charger with automatic switch off and low standby consumption
- Battery life at least 14 days
- Durable Mechanics,> 7 years

Then I'll buy perhaps the fourth model.