Force Macbook Pro on AC mode using broken battery
I noticed the performance issue is because of the battery issue. When battery is not recognized by the OS X86PlatformPlugin (Can be seen in disas, but need confirmation) uses CPUFloor of your device model plist in /S/L/E/IOPlatformPluginFamily.kext/Contents/PlugIns/X86PlatformPlugin.kext/Contents/Resources/.

The issue was battery does not recognized on boot and for MBP 2015 13" CPUFloor==800 which is too low. 

BTW thanks to PikerAlpha you can use freqVectorEdit.sh to change your PowerManager plist. I also changed CPUFloor to higher number so MBP can be used smoothly again.