For cars with gas engines, the cables only need to be sufficiently large to operate the starter motor, which is only a few seconds at a time. So that answer is no, the originally installed cables are sufficiently large. For those of us who have the more abundant, battery-operated cars, the answer is somewhat more complicated. The short answer for us is, yes and no, depending on what we expect from the cart or if changes have been made to the motor or controller.
If the car is absolutely bone material (all original without upgrades) and is mainly used as originally intended for the local course, the standard 6 AWG (also known as 6 gauge or # 6) cables are fine. The wire (cable) is measured with a standard called American Wire Gauge or AWG and refers to the diameter or cross-section of the copper conductor itself. The smaller the AWG number, the larger the diameter and thus the greater the flow capacity. For example, a 2 AWG cable is larger than a 4 AWG that is larger than a 6 AWG. Most car manufacturers use 6 AWG cables. The best cables we have found so far are made by MaxiLink.com, which are super flexible and made for use by extreme tax vehicles.
Ok, now for you who want better performance, we get a bit more technical. The maximum current that ever passes through your cables is when the car is at rest and you press the accelerator on the floor. At that time, the controller performs the maximum power that it can and the motor experiences what is called a "locked rotor" current collection, which can be hundreds of amperes. When the engine is in a blocked state, it needs a huge amount of energy to run it to the nominal RPM. If the engine were to remain in the blocked state (if there was a mechanical limitation that would prevent it from turning), the high current would be absorbed by the motor until it actually burned the windings. Usually, however, the engine starts immediately and the current falls within a few milliseconds (on a storage cart) to 20 or so. There are four things that limit that maximum flow; the resistance of the internal windings of the motor, the current capacity of the battery, the capacity of the controller and the resistance of the battery cables. The battery pack and the motor windings are almost fixed values. Keep this in mind, because we will return to them.
Aftermarket & # 39; high torque & # 39; or & # 39; high speed & # 39; engines that have been installed to improve the performance of the cart are commonplace nowadays. Unfortunately, that extra performance requires extra power. The engine is only to convert electrical energy into kinetic energy (also not very efficient). Powerful motors have a lower internal resistance than stock, which in turn draws more power. If you remember from the science class, power (in watts) of voltage (E) is multiplied by the current (I). Since the voltage can not be higher than the 48 volts of the battery (or 36 volts), the current increases to meet the power demand of the motor. Unfortunately, here comes the resistance of the battery cables around the corner. As the current increases in a conductor, power is lost in the form of heat at a rate of I 2 R, where R is the cable resistance. In an ideal cable and to transfer maximum power, the cable resistance (R) must be zero ohm. Unfortunately, all cables have some resistance. The cable resistance causes the voltage to drop (E = IR) and results in a loss of power to the motor. The solution; increases the battery cables (the larger the cable, the less resistance). Of course, the cable diameter can only be increased within reasonable mechanical size limits, but that is what is needed to take full advantage of a high-power aftermarket engine. Our example used the locked rotor flow to explain the effects of the worst cases. They are less intrusive with partial accelerator, where the power consumption is considerably less. However, if you want to do the dragracing, burn-outs, wheelies and the like with your car, then you need the larger cables to deliver the required mass flow to the engine. Although the resistance of the cables seems small (# 6 = 0.00047ohms / ft vs. # 2 = 0.00015 ohm / ft), the voltage drop is considerable when large currents are present, which will reduce performance. So for the users of high-power motors out there, use cables with a large diameter and keep them as short as possible. Size is important to you. Look for other Randy Wade articles and check out www.digitaloverdrivesystems.com regularly for news, tips and performance products, including the new Maxilink Extreme Duty EV cables.