Kerry Wan/ZDNET Follow ZDNET: Add us as a preferred source on Google. ZDNET’s key takeaways Clearing cache speeds up a slow Galaxy Watch. Cache buildup causes lag and battery drain. Restarting isn’t enough — manual cache clearing helps. Your Galaxy Watch is not so different from your phone or even a messy room. When put to great use, it, too, gets cluttered. By continually using your Galaxy Watch, regularly switching between apps and functionalities, or running too many apps at...

A vivo phone has just been certified for sale in China by MIIT, and this process has revealed its battery size. According to rumors, this will be either the X300 or the X300 Pro, both expected to become official in September or October at the latest. The device has a rated battery capacity of 6,375 mAh, which will undoubtedly be advertised as a typical capacity of 6,500 mAh. While we don’t yet know exactly which X300 model this is, note that the X200 has a 5,800 mAh cell and the X200 Pro c...