My battery drains after 10 hours of non-running.

Something is draining it.

To troubleshoot it, I need to see how much the battery is getting drained and play with all accessories.

How can I check how much is being drained from the battery with the car off?

 

Connect an ammeter in series with the battery positive or negative terminal. You will see the amount of current being drawn from the battery. Turn the dome light off so it doesn't add to the current with the door open.
Normal parasitic drain with the car off should not be more than 100-200ma give or take. If it's draining the battery in 10 hours it's going to be much higher than that.
To find the source of the drain, pull fuses one at a time while the ammeter is connected. When you find the responsible device/circuit you'll see the current drop to normal. Don't forget about any aftermarket stuff in the car that has full-time power (alarms, amps etc.).
Oh, and make sure you don't try to start the car while the ammeter is connected

 

Thanks. Will do.