My Piaggio Quartz 50 from 1992. Got it broken, rebuilt the engine. Has probably over 25000km on it and now runs like a charm. For me it's the most fun and fastest
The Piaggio Quartz replacement Motorcycle Battery (12V 3.5Ah)
Piaggio NTT Quartz 50CC Scooter and Moped Replacement Battery - This is an AJC® brand replacement.: Amazon.de: Electronics & Photo
Universal - GES 6N2-2A Battery Replacement
New AGM Battery For Aprilia 50 Mojito / Rally / Scarabeo / SR50 / Sonic Scooters | eBay