Mine takes a couple hours to fully charge to 100%. Usually I charge it before bedtime so I can use for sleep tracking which uses about 15% of battery. So I got about 85% left when I woke up. My current watch software is BUI5. My GW4 has all sensors turned on continuously, and WiFi is on. AOD is off
I have a habit of using "Close all" on the watch. It's closed all app's that were previously opened. Maybe that's why I got a full potential of watch battery usage.