Nissan Leaf; Pilot signal not being followed

Integrations OpenEVSE
#1

Hi all!

Have just taken delivery of my EmonEVSE unit in order to charge my Leaf from excess solar PV output, replacing a dumb Rolec wallbox. Pleased so far with the unit, however I have noticed now we have some actual sunny days that the car does not seem to follow the pilot signal properly. Most noticeably it either cuts off when the pilot drops below 8A or charges at full power regardless of the pilot value when charging comes on. PS: Max charging limit is set to 15A presently due to temporary small gauge cables/connectors supplying the unit. That does seem effective. Indeed if I adjust this value up and down the car responds accordingly. I have not tried poking at RAPI interface yet, just the web UI.

Here is a screenshot of what I can see when it solar kicks in:

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I also noticed that the car limits charging to ~2-3A less than the pilot. This seemed like some sort of calibration error in the duty cycle and may explain the cutoff at 8A behaviour.

Any idea what’s going on here? What can I test to try and debug this?

Stu

#2

OK so I poked around with the HTTP & MQTT APIs and using a manual override I can make the following observation: the car seems only to respond to the “charge_current” command to update the pilot a few seconds AFTER it starts charging and only if the value is CHANGED. It remains 2-3A lower than the pilot once it starts responding. Perhaps this is ‘normal’ behaviour for the Leaf? Mine is a MK 2 from 2018 with the 40kWh battery if that helps…