I have never seen a shrinker manual.
I have 2 shrinkers for personal use. When you pedal the assist kicks in. Or you can just use the throttle.
This year I replaced my batteries. If you have the black ones that I received I had to take the batteries apart and reverse the insides to get the lights to the back. This however does make the charging plug difficult to get at. I cant recall exactly what I did but I do recall taking them completely apart to get them together the right way. If you can't figure it out upload some pictures.
Gary