Sadly, it is pretty hard.
Most factory made e-bikes would have shitty batteries. Most of them won't have balancing circuit (which is important, otherwise battery becomes useless withing a year), or no actual fuse (this is the reason why hoverboards were catching fire, they rely on N-channel mosfets to cut power, but chinks forgot that mosfets fail short circuit, which means with enough current, protection will fail, and without real fuse, wires will glow red hot).
That said, YOLO, I was driving (riding?) an electric scooter with real hoverboard batteries in backpack. I added fuses though. I didn't even bothered replacing BMS with one that has balancing. >>1371710
Yes. I accidentally motor like that.
Back in the day, when I had E-TWOW, I pushed 20A no problem into the wheel, It lasted me over 1000 km (then batteries died, because of water, but that is another story). Then I had cheap E-TWOW clone, and I pushed same 20A, it lasted 800 km, and I moved to another country...
Ninebot wheel is so fucking weak, it smoked at 20A and stopped working, despite oil I added to cool it. I have no idea why this shit is so popular.