Since I’ve stopped following eScooters closely, I learned of this only today via a YouTube Recommendation.
I just purchased my Ninebot Segway ES2 less than a month ago, added the extended range battery shortly thereafter and within a few days, it started developing a few issues. I will be reaching out to the eBay seller I purchased it from with hopes I can get it repaired/replaced.
There are other interesting Comments at the video. He’s reporting on the ES-2. I don’t know if the ES-1 also has this issue.