I put my MBP 2019 on sleep for 2 hours, came back, battery is drained

[Super Spartan]

First time using a MacBook, I put the laptop on sleep and went to the gym for 2 hours, when I turned it on, the batter was 0

I have an Ethernet cable connected via a USB-C to Ethernet Adapter from Belkin and an external HDD, could the have drained it this fast to what? Even if it was powering them still that is too much of a power draw for a laptop on sleep.

This is on a fresh install of Catalina 10.15.1

 

[Honza1]

Obviously, it did not go to sleep but was running with lid closed (I assume that is how you "put on sleep"). Closing lid may not put it to sleep under some conditions, since you can run it with screen closed but attached to external monitor and not want it to sleep.
It could be the external drive. Recharge and try without the drive. Or some other process is forcing it not to sleep.

If you want to figure out what is preventing sleep, use in command line command "pmset -g assertions", this lists bit cryptic list of processes preventing sleep. In my case I get this:

...$ pmset -g assertions
Assertion status system-wide:
BackgroundTask 0
ApplePushServiceTask 0
UserIsActive 1
PreventUserIdleDisplaySleep 0
PreventSystemSleep 0
ExternalMedia 1
PreventUserIdleSystemSleep 0
NetworkClientActive 0
Listed by owning process:
pid 77(powerd): [0x0000397300088df5] 07:10:53 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"
pid 125(hidd): [0x0000661600099441] 00:00:00 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4294978568.3"
Timeout will fire in 600 secs Action=TimeoutActionRelease

and this states (I think) that system will not sleep for two reasons - I am active AND I have external media (disk) attached...

 

[Super Spartan]

Obviously, it did not go to sleep but was running with lid closed (I assume that is how you "put on sleep"). Closing lid may not put it to sleep under some conditions, since you can run it with screen closed but attached to external monitor and not want it to sleep.
It could be the external drive. Recharge and try without the drive. Or some other process is forcing it not to sleep.

If you want to figure out what is preventing sleep, use in command line command "pmset -g assertions", this lists bit cryptic list of processes preventing sleep. In my case I get this:

...$ pmset -g assertions
Assertion status system-wide:
BackgroundTask 0
ApplePushServiceTask 0
UserIsActive 1
PreventUserIdleDisplaySleep 0
PreventSystemSleep 0
ExternalMedia 1
PreventUserIdleSystemSleep 0
NetworkClientActive 0
Listed by owning process:
pid 77(powerd): [0x0000397300088df5] 07:10:53 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"
pid 125(hidd): [0x0000661600099441] 00:00:00 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4294978568.3"
Timeout will fire in 600 secs Action=TimeoutActionRelease

and this states (I think) that system will not sleep for two reasons - I am active AND I have external media (disk) attached...

I didn't close the lid I just chose Sleep from the top left Apple logo

I'll try again tomorrow without any external drive connected.