This page contains a list of Frequently Asked Questions and their answers.
Can I use the MG LFP280 in combination with the MG LFP304 in one battery bank?
Yes, this is possible. Many systems are using the MG LFP280 battery module. The firmware in both the MG Master LV and HV is accepting these different modules in one battery bank. This is implemented to add backwards compatibility for service and support requests, because the MG LFP304 replaces the MG LFP280 since Mid. 2023. The LFP304 is an upgrade of the LFP280 and therefore can be integrated in systems with existing LFP280 batteries.
Can I use the MG LFP230 in combination with the MG LFP280 or MG LFP304 in one battery bank?
No, this is not possible. In general when designing new battery banks, it is not recommended and supported to use different battery models in one battery bank. For example the MG LFP230 battery module cannot be combined with a MG LFP304.
Why are my LFP batteries not charged up to the maximum charged voltage?
The LFP chemistry has a flat State-Of-Charge vs. Voltage. Only in the higher and lower regions of the curve is it steeper. In the steeper part the cell voltage will show a higher difference between the cells when charging an LFP battery with several cells in series.The BMS is checking for the highest cell voltage and if one cell is exceeding the limit the battery will be considered fully charged. When closer to this cell voltage limit the charge voltage setpoint will be lowered. This results in a lower charge current to fully charge the battery.There is always one cell, the first at the fully charged limit. This will make that the total battery voltage always be lower than the sum of all individual fully charged cell voltage limits. The Fully charged limit is 3.52 V, this times 8 will result in 28.16 V. In practice this means the cell voltage will be around 27.8 V or even a bit lower. This does not mean the battery isn't fully charged, because in the upper region the containing energy is very low. In this top region also the balancing between the cells is checked and marked. The balancing algorithm is taking care of the actual cell balancing of the marked cells.
When to use the MG Master LV PC+ version?
The MG Master LV PC+ version is a standard Master LV but with a higher capacity pre-charge circuit (pre-charge+ = PC+). The maximum precharge capability for the PC+ is around ~1.9F.
For example when using Victron Energy Quattro's the PC+ is recommended for the following numbers:
- 24V 8kVA Quattro more than 4pcs in parallel
- 48V 8kVA/10kVA Quattro more than 2pcs in parallel
- 48V 15kVA Quattro more than 2pcs in parallel
Can 12V Master LV's work as combined system?
Yes, but not all hardware versions support this function.
Only hardware version 0.5 or higher will support the combine function (multiple Master LV's working together as one battery system). Also make sure to install the latest firmware.
Is it possible to connect two MG Energy Monitors in series?
Connecting two MG Energy Monitors in series is no problem. This will work just fine.
Note: once you are going to connected two displays to a Master LV, it is recommended to power the display with an external power supply since the current via CAN-bus is limited.
This external power supply must be always used in case of a MG SmartLink MX, so you will not have that issue there in the first place.
How do I connect the MG Energy Monitors to the MG Master HV?
Connect the MG Energy Monitor to the MG Master HV by connecting an M12 CAN-bus cable Male to the M1 port in the MG Master HV. Please note that the max CAN-bus cable lenght is 1 meter.
A longer CAN-bus cable requires a CAN-bus Isolator/Repeater. Also in this case the CAN-bus cable between the MG Master HV and CAN-bus Isolator/Repeater can have a maximum length of 1 meter.
Can I connect multiple AFC 300 Alternator Field Controllers in parallel?
Yes, it is possible to connect multiple AFC 300 Alternator Field Controllers in parallel.
For example for a motoryacht or commercial vessel with two, three or even more main engines you can connect a second alternator on each individual engine. Always install for each indiviudal alternator an AFC 300 Alternator Field Controller. Establish an NMEA2000 CAN-bus connection between these AFC 300's by using M12 CAN-bus cables. Install on both ends of the CAN-bus an M12 Terminator. The DC power cables can be connected in parallel to the Master LV or to a common DC busbar.