The Megawatt like most Meanwell clones, uses an accessible 1-turn potentiometer that ranges from around 11.5 to 15.5 volts.
By substituting a thermistor within the unit's voltage divider network the sensing system becomes thermally oriented.
By actually working on the units I found the inverse operation (lower the resistance the higher the voltage) has a fundamental useful voltage span that correlates to 280 ohms max down to whatever resistance / voltage level a user desires. In theory a wider scope thermistor can be used to control floating voltages from -40FC to 122F 50C.
The setup is simple - removal of the original pot, solder a length of twin wire with a quarter watt carry potential (24 gauge would be useful to around 60' total back and forth length - meaning a 30' distance between thermistor and float charger.
The beauty of this is that the thermistor could be switched in and out of circuit with a simple ON/ON switch. I am ordering a 16-position single pole click-click switch today, which would allow quite a span in voltage. One side of ON would be thermistor control, the other ON, a manual control. Of course a multi-turn pot can substitute for the click-click switch.
For that matter, another clicky switch can be used as a pull-up with inline resistors for the thermistor. Six ohm increments, and three positions could bias the thermistor. Maybe .1 volt increments negative to plus. It all could be contained in a module with voltmeter and one of Mr. Wizards inductive ammeters.
A fun project.
