Hi. I have problems after disconnecting the battery.
https://www.youtube.com/watch?v=B-cdd-872YI  Anyone know why it does this and how to fix it? 

[2015 Z Force 800 53/Trail EPS]

Classic cold connection symptom..but it could be an open battery cell as well. First re-check all your battery connections as well as the main fuse colder...not the fuse. Then have the battery load tested.