I got all the recommended components - lipo battery and boost converter.I take 3.7V straight to motors and use converter to get 5V that I attached to 5V pin. It looks like that motors and transistors work fine with new supply source. But I see the controller is going to a weird state when I start increasing throttle. It becomes unresponsive and sometimes restarts.
I use this batteries - https://www.amazon.com/gp/product/B074J74S2K/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1I will try to charge them longer and see how it behaves.