MacBook Pro does not switch to battery
Okay, the steps for resetting the SMC on a MacBook Pro with a built-in battery are as follows:


Shut down your computer
Keep the MagSafe adapter (power cable) plugged in.
Press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button
Let go
Turn your computer back on with the power button.


Is that what you did?

Resetting your PRAM/NVRAM

Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). It may be worth you resetting your PRAM/NVRAM, using these steps:


Shut down your machine. Yes, a full shut down, not just logging out.
Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
Hold those keys down until your Mac reboots again and you here the startup chime.
Let go of the keys and let your Mac reboot normally.


Note: When you log back in you may need to readjust some of your system preferences (e.g. mouse speed, time and date/timezone, etc).

Let us know how you go.