Lance Phoenix 150-18T running issue

[peterscooter]

Bought new in crate. When I assembled it, I only finger tightened battery pos and neg. Of course after a few weeks they worked lose and stalled the scoot. But after tightening correctly, the bike won't charge battery. Once started, I can disconnect battery completely and bike keeps running. ...Tried replacing volt regulator (it's 6 pin on the 150-18T instead of the old 4 pin cy6). Still won't charge... dealer told me probably the stat... but why would bike keep running with battery disconnected, plus the stat is a real pain to replace for me without owning a workshop. Anyone familiar or had same problem? Thanks in advance, dawgs!