Mahle MG309 alternator is a high quality 12V 100A replacement engineered to restore reliable charging to marine and light industrial systems. Featuring an insulated ground design for improved electrical isolation, this unit offers consistent output under varying loads thanks to its built in voltage regulator and precision wound rotor and stator. Constructed from corrosion resistant materials with heavy duty bearings, the alternator is built to withstand harsh environments and deliver long service life while minimising maintenance and downtime.

Commonly used in applications including Volvo Penta AQ120 engines, this alternator can be a direct replacement where specifications match but please use the Parts Checker to confirm fitment for your exact engine or vehicle application. Installation is simplified by standard mounting points and connector arrangements that match many original equipment setups. The Mahle design focuses on dependable performance, efficient battery charging, and protection of onboard electronics for safer operation.

• Voltage: 12V
• Output current: 100A maximum
• Insulated ground construction for enhanced electrical isolation
• Integrated voltage regulator for stable charging performance
• Durable bearings and corrosion resistant components for marine use
• Direct replacement form fit and function where specifications align