What does an Alternator do? Quick answer is it powers the electrical system of your car or truck any time the engine is running. It is NOT a battery charger! The battery is the anchor of the electrical system and is primarily used to start the engine. Secondly it acts as a buffer, if you will against voltage spikes and other electrical interference. The alternator will charge a battery but is only intended to replace the energy lost during start up. Using it to charge a dead battery will strain the system and shorten the life of the alternator. Along with bringing the battery back to full charge after start up, the alternator powers all the other loads on the car. It will vary the voltage and amperage as loads change to maintain the battery and power things such as Air Conditioning, Power Seats and Fuel Systems on modern cars. The Alternator must be able to keep up with all the loads on the car without drawing anything from the battery.
It is not hard to see that there is more need for power in modern cars and trucks. From electric windows and seats to computer controlled suspension and brakes, everything requires power! This has increased the size, or better yet the output of today’s alternator. A 60 Amp Alternator of the 1980’s is now 50-60 amps short to cover the power needed by most cars today. As that amperage increases so does the heat and in Texas that is not a good thing. Manufacturers go to great length to keep the alternator cool. Some add fans or added duct work to force fresh air across the unit. Also as the amps go up so does the cost of the alternator as a general rule. On that note it is a great idea to have a charging and starting system check run on your car at least once a year. With the expense of a replacement alternator or the inconvenience of a break down it is just cheap insurance. Many places will do this for free during regular maintenance. These days we should all take advantage of FREE!