Starting in January of 2009, MinnKota serial numbers started in the below format:

A / NNN / SS / NNNNNN

This code is as follows
A = the Alpha equilivant of the year ie: 2009 = J, 2010 = K, ..... 2016 = Q, 2017 = R, 2018 will be S
NNN = the Julian date the unit was made on. A Julian calender, January 1 is 001 and December 31 (non leap year) is 365
You can find Julian calenders on the web -- Google it
SS = Unit type, MK is trolling motors, AI is battery chargers
NNNNN = the actual serial number of the unit


John