: 1100x1429 px
: June 25, 2018
If belt tension is correct, then the next item to check is the alternator itself. You now have two choices - you can test the alternator yourself with a simple test using a voltmeter, or you can have the test performed by a professional. If you choose to do the test yourself, then you will need a DC voltmeter, or a multimeter. Such a unit can be purchased at most auto supply stores, hardware stores, department stores, home improvement stores, etc.
An auto battery is built up of six cells, each containing stacked positive and negative lead plates. These are divided and separated by insulators and immersed in an electrolyte, a liquid blend of sulfuric acid and water. However, some batteries, use a gel instead of the electrolyte. This is considered to be safer and because you do not have to refill it with electrolyte, it has been labelled "maintenance-free". Each cell generates or more correctly put, stores 2.1 volts for a total of 12.6 volts.