I have a Heliotrope RV-30DE solar charge controller. It does not have a remote temperature sensor for the batteries. It would extend the life of the batteries if the controller sensed the temperature right at the batteries.
Anyone know what type of thermocouple required? (E.g. Type J or K, grounded or ungrounded)
Even sharing the color, or any markings on the wire would help.
We have the same solar controller, so I'll try to measure the thermistor sensor this week. Pretty sure it's just two-wire floating thermistor and not a thermocouple.
You can also call AM Solar, who used to sell those controllers (they sold ours) and see if they know the type of sensor and where to get one. They're great people and would probably be happy to help.
If it's a 10k ohm sensor any hvac supply house should have one, or industrial supply, very common.