To understand why your laptop’s battery could be draining even when it is in hibernate mode, there are few steps you should take:

1. Review Battery Health: Check your laptop’s health by using Windows or System Utilities software to review the anticipated battery life, cycle count, and battery temperature.
2. Check for Background Programs: Ensure that all unnecessary background programs and software have been disabled or uninstalled in order to minimize power usage.
3. Review Unneeded Peripherals and Devices: Ensure all printers, monitors, USBs, or other peripherals are unplugged when not in use to reduce power consumption.
4. Check for Outdated Drivers: Update your laptop’s drivers in order to ensure that all components are operating optimally and do not eat unnecessary power.