HM‐400, 2x410Wp, 150 35 MPPT, Pylontech 2,4kWh 48V HM‐350, 1x410Wp - hoylabs/OpenDTU-OnBattery GitHub Wiki
Hey folks, I want to start with a big thank you to the project contributors! I love to see what the community created. Since the examples were super helpful for building my system, I want to share what I did with you as well.
Safety Note: I am no electricity expert and this is no reliable advice. If you want to build something similar, you should know what you are doing.
The setup and how it works
My setup consists of 2 components:
- My legacy system: A 410Wp solar panel with a Hoymiles HM-350. The system is not controlled and directly pushes the produced energy into the household system
- The new battery system (openDTU on Battery)
- The generated energy from the 2x435Wp panels is primarily used to cover the household needs (which is the real need minus what is already produced by the legacy system). Open DTU does this using the "Solar-Passthrough" functionality: It tries to optimize the inverter output so that no power is imported from the grid. Note that in my case, the maximum power provided can be 400Wh (limit of the inverter)
- All solar energy that is not needed to cover household needs, is used to charge the battery
- In case the household needs more energy than what is produced by the solar panels (e.g. at night), the battery is discharged.
The components
These are the components that I used for my setup. I'll also put some prices there to give a rough estimate of the costs.
| Element | Amount | Price | Notes |
|---|---|---|---|
| Trina TSM-435-NEG9R.28Vertex S+ Glas/Glas | 2 | €94.00 | Solar power modules |
| Pylontech us2000c | 1 | €599.00 | Battery 2.4kWh |
| Victron Smartsolar MPPT 150/35 | 1 | €222.37 | Battery Charger |
| Open Battery Platine | 1 | €20.00 | Open DTU on Battery basis Platine from LukasVFL99 |
| Circuit breaker 2 pole 20A | 2 | €15.00 | For solar modules |
| Circuit breaker 1 pole 20A | 1 | €11.39 | For inverter Hoymiles |
| 10m solar cabel 6mm2 | 1 | €32.00 | |
| Rail | 1 | €5.83 | Rail for the circuit breaker |
| ESP32 NodeMCU Development Board | 1 | €8.80 | |
| Ferrules 6mm | 1 | €5.40 | |
| NRF24L01+ | 1 | €8.30 | Antenna for communication with iverter |
| Holzbrett | 1 | €0.00 | For the construction |
| Hoymiles HM-400 | 1 | €99.00 | Inverter |
| MC4 Y Verteiler | 1 | €7.99 | |
| Cabel for inverter to power outlet | 1 | €10.90 | |
| Construction for the modules | 1 | €75.00 | |
| Cabel lugs | 1 | €12.98 | |
| BusBar | 1 | €24.99 | |
| Pylontech battery cabel | 1 | €15.00 | |
| JST 2.0mm PH 4 Pin | 1 | €7.99 | For VE Direct connection. Usually cheaper but I bought multiple cables in the set |
| TOTAL COSTS | €1,384.94 |
My current settings
Since I found it quite challenging to understand the setup and set everything up properly, I will also share my current settings here (still to be optimized)
Dynamic Power limiter Settings
| Setting | Value | Notes |
|---|---|---|
| General | ||
| Enable | True | |
| Enable Solar-Passthrough | True | |
| Battery drain strategy | Empty at night | |
| (Full) Solar Passthrough Losses | 3 | |
| Target power consumption from grid | 0 | |
| Hysteresis for calculated power limit | 20 | |
| Lower power limit | 30 | |
| Upper power limit | 400 | |
| Power meter | ||
| Inverter is behind Power meter | True | |
| DC / Battery | ||
| Battery SoC - Start threshold | 30 | |
| Battery SoC - Stop threshold | 16 | |
| Battery SoC - Start threshold for full solar passthrough | 85 | |
| DC Voltage - Start threshold | 50 | |
| DC Voltage - Stop threshold | 49 | |
| DC Voltage - Start threshold for full solar passthrough | 100 | For the Voltage pass through settings I properly still need to do some better setup |
| DC Voltage - Stop threshold for full solar passthrough | 100 | |
| DC Voltage - Load correction factor | 0.001 | |
| Restart Hour | 0:00 |