The battery provides energy to the starter motor to crank the engine to get it going. Once the engine gets running, the alternator, driven by the engine, generates the electrical energy required by whatever is turned on in the system. The alternator restores to the battery the energy that was used in operating the starter motor. Of course, the restoration of energy to the battery is called charging the battery.

The battery acts like a buffer or a stabilizer, a ballast, an electric shot absorber. At the times that the alternator’s speed is too low to supply all of the demands of the system (the system load), the battery fills in. It also absorbs any excess energy the alternator may produce. We want to take good care of this guy!