The Statcon Energiaa SEOG off-grid solar PCU has a serial port on the back, and it doesn't take much effort to read some monitoring data from it.

I wrote some code to decode the PCU's status, based on example data that Statcon technical support provided on request.

I run this on a Raspberry Pi that's connected to the PCU's serial port using a random serial-to-USB cable:

pi@shikra:~ $ lsusb -s 1:4
Bus 001 Device 004: ID 1a86:7523 QinHeng Electronics CH340 serial converter

The code works well enough that I prefer it to climbing up a ladder to the battery room to read the machine's tiny display (which is admittedly not a very high bar). The interpretation of a few fields is not entirely clear; see below.

pi@shikra:~ $ ~/seog-status.py
2024-12-19 17:55:25.187134
<<< 524608f8000901f10063004f0000000028421501000007c66e79426e6e6e6e6e6e6e796e6e
Inverter status: R
Load on: F
AC voltage: 229.6V
AC current: 0.9A
Battery voltage: 49.7V
Battery current: -9.9A
PV voltage: 7.9V
PV current: 0.0A
PV power: 0.0kW
PV units today: 10.306kWh
PV units total: 35.24kWh (scale guessed)
PV units this month: 1.99kWh (uncertain)
Battery status: y
Charging status: B
PV under voltage: y

• The battery current is reported as an absolute value. How does one know if it's positive (charging) or negative (discharging)? I hoped the "charging status" would tell me, but it only shows "B" so far.

• Is there any way to get the current load? The display does report a percentage and "Load on solar", so it should be possible.

• I don't know how to decode the monthly cumulative total PV generation value.

I run this code against a 5kVA/48V PCU (SEOG-048-5K0-1P). I imagine it would work with other models of Statcon Energiaa inverters, but I don't know for sure.

Released under the MIT license.