Generic battery: 12N9-4B-1 9Ah
Parts Unlimited: rcb-9b
Note: these are regular lead acid batteries priced at $30-$60. Many riders have tried to use AGM (sealed) batteries only to find the dimensions do not fit the battery box on the Chetak.
Recommendation: Use the former bajajusa owner's trick of petroleum jelly on the battery terminals and you will never have battery post corrosion problem.