The battery life of a Philips Sonicare toothbrush on a full charge can vary depending on the specific model and usage patterns. Generally, most Philips Sonicare models are designed to last about two weeks on a single full charge with regular, twice-daily use. Some advanced models, especially those with smart features, may provide additional functionality and could have different battery performance. It is important to note that factors such as brushing intensity, frequency of use, and the specific features enabled on the toothbrush can affect battery duration. Users may also notice that the battery life can diminish over time as the battery ages. For the most accurate information regarding battery life for a specific model, it is advisable to refer to the user manual or the product details available on the Philips Sonicare website. This will provide the best insight into the expected battery performance for your particular toothbrush model.