USB Charger Causing Electrical Gremlins

Hi Everyone,

https://www.amazon.ca/gp/product/B00OGYUGHI/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Above is the unit in question.

With it connected, seems to work for a bit, but then at random, when pressing the starter, the bike completely loses power, lights go off (they were on when the key was turned on) the clock dies and everything.

Pulled the seat, and I did find that the negative screw had come loose (called myself nine kinds of idiot), tightened everything up and turned the key back on and the same thing happened.

Disconnected the USB charger and everything went back to normal, lights on bike started like a champ. Any idea as to what conditions can cause the bike to just shut off like that?

 

Could have been the loose connections. That really should have not made much difference.