Having restored 30 plus cars, here are my recommendations:
Batteries need to be group 31 with 130AMP HOUR! Important to have correct amp hour.
charger:
I’m not a fan of Zivan or Delta-q.
Ride for Fun Super Charger is the best, however Quickcharge in Oklahoma makes the 72v 10 amp charger for them, you can order it direct from them for about $400. It completely charges batteries 100% and comes with a 3 year warranty and automatically float charges.
Zivan only get to 90% and Delta-q is about 90% as well
I would sell your existing working charger on Ebay for $325.
If your existing charger is dead, they still do $100 on Ebay. Go figure.
motor:
Ride for Fun has the best motor at $900, including reprogramming.
Installation takes 30 minutes and speed increase is 10mph another 5 mph with bigger rims and tires.
72 volt converter:
If you have the obsolete circuit board below your main relay switch (far right on dash), call any dealer for free upgrade under recall to Surepower conversion kit. ($650) part free, that will take care of any 12v electrics.
With the right batteries, new charger and motor, these cars will run trouble free for years. Always top off wet batteries with distilled water every 2 months and always store car or batteries indoors in the winter, don’t let them freeze…