Hi @Gary Boyd ,
If you can't get the manual for the correct year check what voltage value is stamped on the brake light or headlight bulbs.
This will tell you what the battery voltage is.
It should also be written on the battery. If it is no longer there on the 1983 model it is a 6V 2AH battery
[https://www.mopedarmy.com/forums/read.php?2,1000764,1000871|This] link confirms that your year model also has a 6V battery.