What year of Batavus do you have? This is a new breed of animal for me and has me curious. My 76 Bat. VA and 77 Bat. HS-50 both have the same Bosch ignition system. Serves me right for assuming all Bats are the same. I'll try to get the wiring diagram posted on my web site this weekend, but it probably will need some modifications for your moped.
Right now I'm in the middle of modifying the rear wheel hub from the cup and cone bearings to sealed bearings. I'm taking pictues as I go and will have this modification on the web site also. Almost every rear wheel I've been able to locate has shown signs of the bad bearings on the drive sprocket side of the rear wheel. Wish me luck as I try to invent a better mouse trap.
Lamborn's Miniature Engines