Common occurrence.
Electrical bikes are very common here, even some cities don't allow ICE powered ones.
Shenzhen for example the only ICE motorcycles you see regularly are own by the Traffic Police or the utility (gas, water, electricity and the guy who delivers the newspapers) and rarely a neighbour who have one and risks a fine by using it, although in Macao and Hong Kong they are very common.
And as bikes they are allowed to go on the sidewalks (that I totally disagree but that's me). In other parts of China is a mix. Combine that with some subpar construction of said packs, the high energy storage of said packs and the lack of following good security practices and you have a receipt for tragedy. I will one of this days create a topic with the most glaring faults I common see, with pictures, both in electrical installations and battery powered. Let's say I saw my fair share of mind-boggling things, on the worse tense of the sentence...