According to the information available, 336 hours is a theoretical figure (standby), not the runtime during daily cleaning. Depending on the brushing time, mode, pressure, display and Bluetooth, it may be normal for the battery to drop noticeably per brushing session. Please charge the product fully (often up to 12 hours for this series) and then test it for 2×2 minutes without Bluetooth. If it then continues to lose approx. 10 per cent per brushing, this is rather conspicuous. We then recommend a warranty check. In this case, we will refer you to our digitec Assistant, which provides direct contact options so that you can be helped accordingly.

https://www.digitec.ch/help