| magneto has nothing to do with charging battery. mebbe you are meaning alternator ? M/W, remove new battery. Take to qualified shop for LOAD TEST. While batt is removed, take apart all battery cable connections in start circuit. Using sandpaper, clean all connection points including frame and batt post connectors themselves to bright metal. Visually inspect relevant wiring for cracks/frays/etc. Tape up as needed. reinstall known good battery. monitor and post back if still trouble. | 
