The Motor Serial Number is the 10 digit serial number located on the rear wheel hub motor.
The Bike Serial Number can be found at either the lowest part of the frame or the front of the handlebar stem.
The serial number begins with the letters:
“HE004" - DJ Mountain Bike
"HE005" - DJ City Bike
"HE004F" - DJ Fat Bike
"HE004FM" - DJ Fat Bike MD
"HE005F" - DJ Folding Bike
"HE005FS" - DJ Folding Bike Step Thru
"HE005S" - DJ Super Bike
"HE005SS" - DJ Super Bike Step Thru
See the photos for examples.