I have configured EmonCMS to send data to EmonCMS through the charger’s ui and I have 2 problems:
- The wh is sent (and received) every few seconds as you would expect but the EmonCMS input value does not change until I unplug the car.
- When it does update, the wh is about 10% lower than a calibrated meter supplying EmonEVSE
The charger is normally sleeping except between 00:30 - 04:30.
Note it does not send the correct wh value even when awake/charging - it only sends the correct value when I unplug…
Is this normal - if so why?
Does the EmonEVSE wh calculation assume 230V or use actual voltage? I ask as we are typically running 10% higher than 230V and this could account for the wh error.
This is normal behaviour, the total session energy is posted when the charging session is complete i.e car is unplugged
This is probably because the EmonEVSE does not measure voltage directly therefore assumes voltage to be 240V. If you are running OpenEVSE controller firmware V7.0.1 or greater and OpenEVSE WiFi firmware V3.2.0 or greater it’s possible to set the VRMS reading dynamically via MQTT from an emonPi or emonTx to improve the energy calculation accuracy e.g
Thanks for the quick reply.
I have V5.1.0.T2 & Wifi 3.3.0 and it shows the MQTT voltage topic so I could get it.
It’s a bit weird not to use the actual voltage (as it has it) for wh, and to freeze the wh emoncms input until unplugging, but neither are a real problem…
Updating the firmware looks tricky so I thing I’ll leave it alone.