Python lib to talk to pylontech lithium batteries (US2000, US3000, ...) using RS485
What is this lib ?
This lib is meant to talk to Pylontech batteries using RS485. Sadly the protocol over RS485 is not some fancy thing like MODBUS but their own crappy protocol.
How to use this lib ?
First of all, you need a USB to RS485 converter. They are many available online for some bucks.
Then, you simply need to import the lib and start asking values:
>>> import pylontech
>>> p = pylontech.Pylontech()
NumberOfModules = 3
Module = ListContainer:
NumberOfCells = 15
CellVoltages = ListContainer:
NumberOfTemperatures = 5
AverageBMSTemperature = 29.81
GroupedCellsTemperatures = ListContainer:
Current = -3.5
Voltage = 49.59
Power = -173.565
RemainingCapacity = 39.5
TotalCapacity = 50.0
CycleNumber = 5
-->8-- SNIP -->8--
TotalPower = -525.8022
StateOfCharge = 0.79
CellHighVoltageLimit = 3.7
CellLowVoltageLimit = 3.05
CellUnderVoltageLimit = 2.9
ChargeHighTemperatureLimit = 33.41
ChargeLowTemperatureLimit = 26.21
ChargeCurrentLimit = 10.2
ModuleHighVoltageLimit = 54.0
ModuleLowVoltageLimit = 46.0
ModuleUnderVoltageLimit = 44.5
DischargeHighTemperatureLimit = 33.41
DischargeLowTemperatureLimit = 26.21
DischargeCurrentLimit = -10.0
python-pylontech needs python 3.5 or greater (but please, use at least 3.7 or more if possible to be future-proof).
This lib depends on pyserial and the awesome construct lib.
The pylontech modules talk using the RS485 line protocol.
The first DIP switch on the pylontech indicates the line speed. It must be off (0, down position) so that the speed is set to 115200 Bd.
The RS485 port is exposed on the pins 7 & 8 on the RJ45 connector names RS485.
Any RS485 to USB (TCP/IP not yet supported) converter should would. You just have to wire the two pins above to the A and B ports (swap them around if it doesn't work). of your converter.
I personally use cheap chinese "RS485 to USB" converters worth a couple of bucks each.
Mixing between US2000 and US3000
If you are using US2000 and US3000 batteries, then the main battery must be a US2000. Please see bug https://github.com/Frankkkkk/python-pylontech/issues/2#issuecomment-915966564 for more information