Power capacitor work by acting as a reserve power bank by storing the charge rather than being the source of power just like a battery. Whenever you are listening to music or playing a movie, the power will be draw from the capacitor rather than from the battery so as to ensure the rest of the car will not be starved of power. It also serves as a buffer so that the power being delivered to the amplifiers will not drop below the recommended voltages and be steady thus reducing the risk of damage to the components. The use of provide several benefits but it is crucial to have a good understanding of capacitor so that the two can be related together.

So what power capacitor to choose?

After doing some research, the general rule seems to be 1 farad per 1000 watts of power that your system is running at. So, using 1.5 farad power capacitor should be ideally suited to a 1500-watt system. There is a large selection of power capacitor designed for various use, for instance, a power capacitor of 2 farad can be designed for smaller system, this does not imply that it would have a reduction in power but for those systems that require more power, a power capacitor with a higher farad will be able to deliver for a long period and will usually be of higher build quality.

How to install the capacitor

The ideal thing is to install a capacitor very close to the amplifier. The capacitor requires a 12-volt positive from the battery and a separate ground to the amplifier so that the 12-volt positive is ‘inline’ with the terminal from that battery and the amplifier. The amplifier 12 volt positive is then taken from the capacitor while the amplifier is usually grounded separately as it is essential to use short ground cable so as to reduce any potential ground interference.

When you need to consider other alternatives

Power capacitors will not always be of help when you are listening to music, if the lights for example dim down, and stay dim, this indicates there is a deficiency of power and there are other methods of solving the problem, it could potentially be that the battery is not able to generate a charge sufficient enough to meet the demands, so installing a higher cranking battery is usually the common solution however it is possible that upgrading "The Big Three" may also solve the issue. It is also important to check that the current alternator can produce a charge that will be sufficient with a larger battery.

Having discusses about capacitor bank, the major reason why reactor is used in them is because it reduces the current transient at the instant of switching on the capacitance. In the absence of such reactor, the contacts may get damaged at power-on. At main frequency, reactance of the inductor is very small when compared to inductance of the capacitor. However, for step functions, the inductance offers high reactance thereby limiting the current to a safer value.