MG Energy MG AFC 300
AFC 300 Alternator Field Controller
The MG AFC 300 is an alternator field regulator.
It controls the alternator to charge an MG Lithium-Ion battery system. By controlling the field inside the alternator, the current from the alternator can be regulated. Together with a current and a temperature measurement on the alternator it can be protected from overheating. This also allows the AFC 300 to follow the setpoints from the connected BMS to charge the battery system under optimal conditions.
The AFC 300 has a build in load dump to protect the alternator, the AFC 300 itself and any connected peripheral equipment. If during the charging phase of the alternator the connected fuse breaks or the main safety contactor inside the BMS opens the AFC 300 will stop the charging of the alternator as quickly as possible and will clamp the voltage overshoot.
The AFC 300 supports a wide variety of alternators compatible with external field control. As long as one or both field wires come out of the alternator it can be connected to the AFC 300. The AFC 300 is capable to automatically sense what kind of field is connected. This way there are no different cable harnesses needed for different kinds of alternators. The AFC 300 supports 12 V, 24 V and 48 V battery systems.
Interfacing to the BMS is done through M12 CAN-Bus connector. And can be connected to a variety of different BMSs including the MG Master LV, MG SmartLink MX and MG SmartLink Connect. The standard CAN-bus protocol is based on NMEA2000. No additional EMS or PMS is needed, because direct control is possible.
To adjust any settings it is possible to directly connect to the AFC 300’s build in Bluetooth module using the MG Connect App. The Bluetooth module can also turned off by a hardware switch if this is required.
Key features:
- Alternator protection
- Temperature and current regulation.
- Automatic field polarity detection.
- Integrated load dump protection.
- Programmable digital input & output.
- Isolated M12 CAN-bus.
- NMEA2000 and DVCC compatible.
- Bluetooth for easy configuration.
- Fully encapsulated electronics for harsh environments.

BMS Controlled
When the MG lithium-ion batteries are fully charged, the charge voltage limit will be automatically lowered by the BMS. The AFC 300 will always follow this parameter from the BMS via the NMEA2000 CAN-bus.
Temperature protection
The integrated shunt continuously monitors and controls the current and temperature status of the alternator. This protects the alternator against overtemperature


Load Dump Protection
The built-in Load Dump Protection, a software and hardware overvoltage protection, shields the power electronics and alternator from damage in case of an emergency shutdown.
More MG Blue in Your Engine Room?
The MG AFC 300 alternator regulator protects the connected alternator, ensures optimal battery charging, extends battery life and enhances system reliability.
Thanks to the NMEA2000 compatibility it communicates and works seamlessly with both the MG Master LV, SmartConnect Series and the SmartLink.
In order to ensure optimal functioning, the AFC 300 is compatible with MG battery systems only.
Bluetooth makes it easy to configure and monitor the system with the MG Connect app on your phone. Its advanced features make it an essential device to complete an alternator powered MG battery system.

The Flexible AFC 300
The AFC 300 is suitable for 12 V, 24 V and 48 V alternators and capable of handling currents up to 300 A. Automatic Field Polarity Detection can control both N- and P Type alternators.
Parallel
Connect multiple MG Alternator Field Controllers in parallel and the current will automatically be divided equally. When multiple chargers are connected, the AFC 300 will regulate the current accordingly.


MG Connect App
With the built-in Bluetooth it is possible to configure the AFC 300. Download the MG Connect app to set the temperature and current parameters. Furthermore, use the app to monitor the device parameters, read-out the alternator RPM, perform diagnostics and update to the latest firmware.
| Selling Unit | EACH |
|---|---|
| Model No | MG AFC 300 |
| Brand |
|
| Original Brand | MG Energy MGAFC480300 |
| Description | AFC 300 Alternator Field Controller |
| Width | 255mm |
| Height | 63mm |
| Length / Breadth / Depth | 132mm |
| Weight | 1.5kg |
| Categories |
Power Products & Accessories Battery Management & Monitoring MG Energy MG Energy Distributors |
| Data Sheet |
|
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MG Connect
MG Connect provides an overview of key values of all nearby MG devices, shows live system data and provides insights into your energy consumption with historical data. Find out more at MG Energy.