Off Grid Solar Notes
This page is dedicated to documenting the off-grid solar setup. This page is a work in progress.
Solar Panels
Yes.
MPPT
Victron Energy MPPT
Inverter
Zetawale GXTK-48V-2500
Protocol Decoding
Since the inverter speaks with a protocol that is not documented anywhere, we have taken the effort to decode it.
The first prototype involved attaching sigrok to it. We used a commonly available decoder featuring the Cypress / Infineon EZ-USB FX2LP and wrote a pulseview decoder in python:
The "final" version involves a hardware and software component. The hardware is built using this inverter board from Brandon and this firmware. The software which sends the inverter data across the HAL network and into our display can be found here.
At the time of this writing, the hardware that is placed on the wall at MAG Laboratory is very not "final."
Battery
48v EG4 LL with old firmware
The battery sender which sends battery data across the HAL network can be found at this link.
Register Map
| Address | Description |
|---|---|
| 21 | SOC |
| 22 | Voltage |
| 113 | Cell 00 |
| 114 | Cell 01 |
| 115 | Cell 02 |
| 116 | Cell 03 |
| 117 | Cell 04 |
| 118 | Cell 05 |
| 119 | Cell 06 |
| 120 | Cell 07 |
| 121 | Cell 08 |
| 122 | Cell 09 |
| 123 | Cell 10 |
| 124 | Cell 11 |
| 125 | Cell 12 |
| 126 | Cell 13 |
| 127 | Cell 14 |
| 128 | Cell 15 |
Emergency Charger
The solar system has an emergency charger which moves on-grid energy into the off-grid system.
The emergency charger can be remotely activated using the following commands on MQTT:
| Action | Topic | Message |
|---|---|---|
| Turn On | plug0-battery-charger/cmnd/POWER | on |
| Turn Off | plug0-battery-charger/cmnd/POWER | off |
Monitoring
The following intranet links will redirect you to our internal grafana dashboards.