Q: 45W MagSafe2 power supply got hot, smells burnt

Depending on your country and location, some rules may vary, and if you have a valid

concern with your power supply you can ask an official Apple Store to check & inspect

the part (and also recommend the computer be checked into as well) to see what the

problems may be. To run the battery flat is never a valid approach since those batteries

will not ever fully recharge again if that is allowed to happen.

• About Mac notebook batteries - Apple Support

• Apple Portables: Troubleshooting MagSafe adapters - Apple Support

There may be some conditional consumer laws, in certain areas, say in the EU or the UK

that may be worth considering; which may apply to your power adapter. As I'm in neither

of those regions, all I can do is suggest you attend to the matter as soon as possible so

as to not allow additional issues or damages to occur. Safety & health are first issues.

• Make an appointment at an Apple Retail Store Genius Bar
• Find an Apple Authorized Service Provider

Inquire of an official Apple Store with 'genius bar' + set Appointment before going there.

Good luck & happy computing!