Extending ESC wires can harm the ESC if not done correctly. We explained the sort of phenomenon that is responsible for the troubles. That can be found here in an article titled, “Why extending ESC wires can be harmful.” Bottom line is that the inductance of the battery input wires can destroy your ESC. You can either extend the motor to ESC wires or you can follow what is below.
How to extend ESC wires on the Battery Input Side
It is possible to extend the ESC wires by adding in a few components near the ESC. The component you must use are capacitors. Capacitors are used in parallel on the ESC battery input wires. These capacitors are best positioned as close as possible to the ESC. They are wired directly across the positive and negative terminals of the ESC in one location. Affiliate Link to Castle Creations Capacitor Bank
It is important to not distribute them along the length of the ESC to battery wires. Doing so will not provide any benefit to the system. In addition, placing the capacitors close to the battery will not be efficient as the battery acts as a much larger capacitor. The inertia in the form of current gets worse as you move down the wires towards the ESC.
What Size and how many Capacitors are required
The capacitors that you will require are to be low ESR( Equivalent Series Resistance) and low impedance. These capacitors tend to be cylindrical in shape and because of this are commonly known for being cylindrical capacitors.
Cylindrical capacitors are polarity sensitive. When you wire them up, be certain that you know which terminal is positive and which is negative. Wiring capacitors to the wrong polarity will certainly cause failure.
The voltage of the capacitor must be higher than that of the maximum voltage of the battery. It is best to also have some head room here as the pulses generated from operation can actually increase the voltage load (higher than the max battery voltage) of the capacitors. Having capacitors that are much higher in voltage is no problem.
The amount of capacitance that you must add when extending ESC wires are 460uf for every 100mm or 4 inches of wire. Keep in mind this is one run of wire and does not represent a double run of wire.
Example of how to Extend ESC Wires
In the example above, the capacitor bank is soldered at the positive and negative terminal posts to the ESC wires. The battery wires to the ESC have been extended by 4 inches. In order to compensate a 460uf capacitor must be used. It doesn’t matter if you require one capacitor or three capacitors to get to 460uf or more. You can place capacitors in parallel to add up to the sufficient amount.
Extending Wires from ESC to Motor
There is no problem extending the wires on the motor side. No risk to the motor or ESC is taken. The worst thing that can happen is possible interference from these longer wire runs. In order to combat the interference, 3 twists per inch of the 3 wires leading to the motor with help.