The charging voltage of Huawei watches may vary depending on the model and version. In general, the charging voltage of Huawei watches is 5V, which is the standard USB charging voltage. However, some models may support higher charging voltages, such as 9V or 10V charging voltages for some models. But in general, 5V is the most common charging voltage for Huawei watches. Please note that if you use a non-original charger or an incompatible charger, it may cause damage to the watch battery. Therefore, you are advised to use the original charger or the adaptive charger purchased on Huawei's official website.