Hi all,
I need a set of good MPPTs and was looking at the EPever range as they appear good quality and rather affordable (compared to Victron ones). I would really like them to have an input that allows to enable/disable them, as is described in the Nordkyn articles (TLDR: enable/disable chargers to ensure correct charge termination, for safety the BMS still drives a relay that can disconnect the LFP battery).
All Victron MPPTs appear to have this feature. The EPevers, however, do not appear so. Of course, I can put relays between the MPPTs and the PV panels but relays would add cost and introduce losses. So, I was wondering whether I could fool around with the temperature sensor functionality of the EPever. This hack should be a reasonably fail-safe one, in case it fails the charger should be disabled.
There was a related thread (https://diysolarforum.com/threads/externally-controlling-a-non-controllable-charge-controller.20136/), however, that thread did not focus specifically on EPever MPPTs.
According to their manual, EPever MPPTs allow to connect an external temperature sensor (TS300R47K3.81A, an NTC?). Furthermore, the manual mentions that if the temperature sensor is not connected or shorted, the MPPT assumes the temperature to be 25 °C. From the communications sheet it appears that an allowed-charging temperature range can be programmed.
So, I was wondering... can one set the maximum battery temperature to 20 °C or so (or minimum temperature to 30 °C or so) and then enable the charger by putting a specific resistance that corresponds with e.g. 10 °C (or or e.g. 40 °C) over the temperature sense terminals? Putting the resistance would be done with a small signal relay or maybe an optocoupler.
Looking forward to your thoughts
I need a set of good MPPTs and was looking at the EPever range as they appear good quality and rather affordable (compared to Victron ones). I would really like them to have an input that allows to enable/disable them, as is described in the Nordkyn articles (TLDR: enable/disable chargers to ensure correct charge termination, for safety the BMS still drives a relay that can disconnect the LFP battery).
All Victron MPPTs appear to have this feature. The EPevers, however, do not appear so. Of course, I can put relays between the MPPTs and the PV panels but relays would add cost and introduce losses. So, I was wondering whether I could fool around with the temperature sensor functionality of the EPever. This hack should be a reasonably fail-safe one, in case it fails the charger should be disabled.
There was a related thread (https://diysolarforum.com/threads/externally-controlling-a-non-controllable-charge-controller.20136/), however, that thread did not focus specifically on EPever MPPTs.
According to their manual, EPever MPPTs allow to connect an external temperature sensor (TS300R47K3.81A, an NTC?). Furthermore, the manual mentions that if the temperature sensor is not connected or shorted, the MPPT assumes the temperature to be 25 °C. From the communications sheet it appears that an allowed-charging temperature range can be programmed.
So, I was wondering... can one set the maximum battery temperature to 20 °C or so (or minimum temperature to 30 °C or so) and then enable the charger by putting a specific resistance that corresponds with e.g. 10 °C (or or e.g. 40 °C) over the temperature sense terminals? Putting the resistance would be done with a small signal relay or maybe an optocoupler.
Looking forward to your thoughts