It may be true that your alternator converts all the mechanical energy made by your engine into electricity to run all your vehicle's electrical devices, increasing its range can really cause a difference. By using an alternating current (in modern cars but older models use DC generators or a direct current), an alternator can charge your car's batteries. But at the same time, it also powers various electronic and electrical components of your car. Alternators may be just some small electrical generator but it can really pack a punch for your car.
Your generic alternator is made up of four parts: the rotor, the stator, the diode packs and the voltage regulator. The rotor is a rotating magnet that rotates around the stator, which a core of iron wrapped in copper wires. These rotor-stator pair rotate within each other and create an alternating current which would be converted by the diode packs indirect current that can be used to charge the battery and power up other electrical components of the vehicle. The voltage regulator controls and maintains the amount of electricity that is made by the alternator.
Powering up a your car's alternator doesn't only mean to have it rebuilt. It has to be properly maintained and checked for defective parts. But to really give it a little boost, alternators have to be upgraded. You really need to buy a performance alternator to complement all your car's energy consumption.