I’m in a “scratching head” moment, first the 11.1 volt battery source is not enough for the watering solenoid and the small solar charger cannot keep up with the drain from the solenoid. But I was testing it 6 or 7 times a day when 2 times a day would be the normal. But I like to err on the side of caution.
So I can use this as a reference:
So the blank center (centre) section has to be filled in!?
So I might put the regulator board back in and power the system (5 volts) from it but still power the watering solenoid directly from the batteries.