The basics of the electrical system in any automobile comprises the battery, the alternator and the starter motor.
The battery is always located in an easy to access position adjacent to the engine, and is used to start the engine and to provide quality regulated DC power to the Engine Systems and the vehicle systems and instruments. The standard battery voltage is 12 volts, and generally the battery is lead acid with six 2 volt internal cells. The battery is rechargeable, both by the alternator and by an external battery trickle charger.
The battery must be capable of delivering extremely high current when starting the vehicle, typically between 100 and 300 amps, and also must be capable of delivering much lower amperage better steady reliable voltage over a long period. The battery capacity as described in terms of ampere hours or AH, and can be 80 AH for a small vehicle and 120 AH or larger for a large vehicle. Go hire the electricians Taupo like the best.
The battery has a positive and a negative terminal, with the positive red cable connecting to the alternator and the negative black cable connecting to the vehicle metallic framework or “ground”. Because of the very high current loads during starting, the cable connections to the battery and other systems have to be large and very firm.
The alternator can be mounted anywhere convenient on the engine, and it is driven by either a belt or gears from the engine. The purpose of the alternator is to recharge the battery, but it also must not over charge the battery so in modern vehicles the vehicle computer system manages this.
The starter motor can also be mounted anywhere convenient on the engine, and it is connected to the engine by very robust gears. The starter motor also has a very large red cable from the positive battery terminal, with the negatives simply being the mechanical attachment to the engine or “ground”. The starter motor engages the engine gears when the ignition key is activated, and disengages from the engine gears once the engine starts.