My Sonicare Battery Wont Charge Sonicare Battery- Charge Daily Or When It Runs Out?

Sonicare battery- charge daily or when it runs out? - my sonicare battery wont charge

The instructions say it should leave the toothbrush on the charger when not in use, while retaining the office for a week. However, my friend said that the type of battery you are using Sonicare, nickel-cadmium is the man who is supposed to work the till to extend charging for his life.
If you have additional information?