If your Sonicare toothbrush is not turning on, simply replacing the battery is unlikely to solve the issue. You can submit an online warranty request for assistance in obtaining a replacement device here, or contact us here. All Sonicare toothbrushes and flossers come backed with a 2 year warranty.
The built-in rechargeable battery can be removed for disposal, and instructions for battery removal are available under Manuals and Documentation for your product here. If you are not comfortable disassembling electronics, we recommend seeking professional assistance at your local electronics recycling or repair shop.
We advise against replacing the battery yourself because it may increase the risk of fire or other potential safety hazards.
Note: Opening the toothbrush will void the product's warranty.