All of a sudden my battery drains over night mac book only 12 months old !

IF your product identifies as "12-inch MacBook retina 2015-2018"

there is no issue. ~ However there have been dozens of builds

named MacBook, from 2006 until recent; and they've evolved.

• Identify your MacBook Pro model - Apple Support

https://support.apple.com/en-us/HT201300

• Identify your MacBook Air model - Apple Support

https://support.apple.com/en-us/HT201862

• Lookup Mac Specs - EveryMac Ultimate Lookup

https://everymac.com/ultimate-mac-lookup/

Perhaps you may supply more exact build model year info?

And support Community hosts could relocate this thread.

• Get help with your Mac notebook battery - Apple Support

https://support.apple.com/en-us/HT204054

• How to reset the SMC of your Mac - Apple Support

https://support.apple.com/en-us/HT201295

• If your USB-C power adapter isn't charging your Mac Notebook - Apple Support

https://support.apple.com/en-us/HT204652

If it's only 12 months old, then in it's not a MacBook. They were discontinued July 2019. It may be a MacBook Air or a MacBook Pro.