MacBook Pro 16 2019 battery drained overnight

I am facing the exact same issue, very frustrating!

Hello dmystp,

Welcome to Apple Support Communities. 

We want you to be able to use your Mac as expected. We recommend the tips as listed here to maximize battery life: Batteries - Maximizing Performance - Apple

1. Update to the latest software.
2. Optimize your settings.
3. Plug in and power on your MacBook to charge other devices.

Tips for Extending Battery Lifespan

1. Automatic battery health management.
2. Avoid extreme ambient temperatures.
3. Remove certain cases during charging.
4. Store it half-charged when you store it long term.

You can also view the energy consumption of your apps using the Activity Monitor as listed here: View energy consumption in Activity Monitor on Mac - Apple Support

View energy consumption in Activity Monitor on Mac

Use the Energy pane of the Activity Monitor window to see the energy use of your Mac. You can monitor overall energy use, and see details about the energy use of each app.

• In the Activity Monitor app  on your Mac, click Energy (or use the Touch Bar).
• To display more columns, choose View > Columns, then choose the columns you want to show.

Let us know if you have further questions.

Take care.

This is exactly what is happening to mine as well. Only since upgraded to Ventura. Charge battery fully. Don't use it for 3 days. Come back, battery is completely drained. So frustrating!! Any solutions yet!?

I am on MacBook Air M1 2020.