Well, The airport security in China have just been given a new job,
This will pretty much impact any NZer travelling within China as Powerbanks in NZ ( or most other parts of the ex-China world) won't likely carry the required domestic Certification, ( despite likely being made in China )
"Discarded batteries are piling up at Chinese airports following the introduction of a snap ban on most powerbanks being taken onto flights.
The new rule, which came into force on Saturday June 28 with only two days’ notice, applies to domestic flights within China – although there are reports of passengers boarding international flights from Shanghai also being caught in the crackdown.
China’s Civil Aviation Administration has declared that only powerbanks which carry a local ‘3C’ (China Compulsory Certification) logo will be permitted on flights.
3C certification is a mandatory safety and quality certification for both locally-manufactured and imported products."
https://www.executivetraveller.com/news/china-airline-powerbank-battery-ban