I attached a 16/2 wire extension cord to the battery terminals. REd to positive, Black to negative posts. Leave the female end on the extension cord.
Leave enough length to the cord to be accessable on the outside of the machine.
Splice the male end of the cord to the end of the charger wires. Red to positive, black to negative. I just sit the charger on a shelf, plugged in to 115 volts.
Sorta like those electric cart arrangements that I use at LOWES, etc.
HTH John,PA You could use 15 amp twist lock electrical ends, if you need to.