To have the battery filled you would have to take it to a local motorist and they should be able to fill it for you.
New For YAMAHA FS1E 50 V80 1.20 x 17 Front Complete Wheel 14mm Spindle
New For YAMAHA FS1E FS1 Exhaust System 1974-1992 FS1-E Chrome Silencer Fizzy FS1
Ignition Coil For Yamaha FS1E (DRUM) 1974-1976
Kickstart Lever Kick starter for Yamaha FS1E FIZZY 50cc (Pedal Model)
For YAMAHA FS1E FS1 Exhaust Nut FS1-E Fizzy RD50 1L41461200
Front Wheel Oil Seal R/H Right For Yamaha FS1E 1990 (50 CC)