For gas powered trolleys, the cables must be large enough to drive a starter motor that lasts only a few seconds. So there is no answer, initially installed cables are large enough. For those of us who have more heavy carts with batteries, 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 engine or controller.
If the cart is absolutely bone material (and all originals without upgrades) and is used mainly as originally intended around the local course, standard 6 AWG cables (aka 6 or # 6) are great. The size of the wire (cable) is measured by the standard American Wire Gauge or AWG and refers to the diameter or cross-sectional area of the copper conductor itself. The smaller the AWG number, the larger the diameter and, therefore, the greater the current carrying capacity. For example, a 2 AWG cable is more than 4 AWG, which is more than 6 AWG. Most board manufacturers use 6 AWG cables. The thinnest cables we have found so far are made by MaxiLink.com, which are ultra-flexible and designed for use in extreme conditions.
Well, now for you guys who want to improve performance, we will get a little more technical. The maximum current that will ever pass through your cables is when the cart is at rest and you knead the gas pedal to the floor. At this point, the controller delivers the maximum power it is capable of, and the motor is experiencing a current drain, which is called a “locked rotor,” which can be hundreds of amperes. When the engine is in a state of theft, its rotational speed is required for its rotation. If the motor had to remain in the stolen state (if there was some mechanical limitation that did not allow it to turn), then the high current will continue to be absorbed by the motor until it actually burns down the windings. Usually, despite this, the motor begins to rotate immediately, and the current drops to 20 or about cycles in a few milliseconds (in stock). There are four things that limit the maximum current; resistance of internal motor windings, current battery capacity, controller capacity and resistance of battery cables. The battery and motor windings are fairly fixed values. Keep this in mind, because we will return to them.
Nowadays, the so-called “high torque motors” or “high-speed” motors installed to improve the performance of carts are commonplace. Unfortunately, this additional performance requires additional power. The engine only works to convert electrical energy into kinetic energy (not very efficient). Powerful motors have a lower internal resistance than the margin, which, in turn, increases the current. If you remember from the scientific class, power (in watts) is the voltage (E) times the current (I). Since the voltage cannot exceed 48 volts (or 36 volts), the current is increased to meet the engine power requirement. Unfortunately, this is where the resistance of the battery cables comes into play. As current increases in a conductor, power is lost in the form of heat at a rate of I2R, where R is the cable resistance. In an ideal cable and for transmitting maximum power, the cable resistance (R) should be zero. Unfortunately, all cables have some resistance. Cable resistance causes a voltage drop (E = IR) and results in a loss of motor power. Decision; increase the size of the battery cables (the larger the cable, the less resistance). Of course, the cable diameter can only be increased within reasonable limits of mechanical dimensions, but this is what is required to take full advantage of a powerful aftermarket engine. In our example, the blocked rotor current was used to explain the worst effects. They are less radical with a partial choke, where the current consumption is much less. If you want to drag and drop, burn wheels, etc. With your trolley, you will need larger cables to provide the necessary massive current push to the motor. Although cable resistance looks tiny (# 6 = 0.00047ohms / ft vs. # 2 = 0.00015 Ohm / ft), the voltage drop is significant when large currents are present, which reduces performance. Therefore, for users of powerful engines, use large-diameter cables and keep them as short as possible. Size will matter to you. Search for other Randy Wade articles and regularly check www.digitaloverdrivesystems.com for news, tips and products, including new EVI Maxilink Extreme Duty cables.
