You might try over here with that question:
https://forum.solar-electric.com/cat...-power-systems
I live off grid and installed my own equipment. The wire length limit for the controller is likely due to voltage drop. In order to charge properly, you have to have as little voltage drop as possible. Having said that, you could probably get away with a little more distance but you really don't want to it to be too long.
Not knowing the wiring diagram, I would wire directly to the battery.