if you have a 24V controller you can check the voltage on the output of the voltage regulator to insure it is not pulled up too high by the higher input voltage. we can walk you through it if you wanna.
when the input current comes in it goes through a power resistor that drops the voltage input to the 12V regulator. if the input voltage is higher than stock, then the power resistor may not drop the voltage that is input to the 12V regulator enuff to keep the output of the 12V regulator within range, ie. 12V on the output.
so if it is too high you can add a little more resistor to the input power resistor to help the voltage regulator handle the voltage it sees on it's input. they last longer that way, and a high output voltage from the 12V regulator can make it hard for the little transistors that switch the high current mosfets if the output of the regulator is above 20V. but for this low voltage it may not be significant. it is when you go to high voltages.
capacitors usually go up in stages, 20V, 35V, 50V, 63V, 100V generally. so your 24V controller may have 50V or 63V caps on the input if it handled the 36V lithium. most mosfets have BVds of at least 50V or so, but some older ones are 35V.