Hey,
We have a 2008 Hisun 700 and it had a similar problem. Would die at the worst times, idled rough, and wouldn't restart. Turned out to be the rectifier/charging unit. Got the part on amazon I believe. Diagnosed it using a pdf from RMSTATOR, they have excellent diagnostic breakdown that really only requires a multimeter. https://rmstator.com/pub/media/pages/static-pages/tests-diagnostic/pdf/electricals-gremlins-20170223-EN.pdf