Sometimes, what people bother so much about turn out to be problems whose solutions are extremely obvious. This conversely means that checks for electrical problems in cars should start at the most obvious locations; the battery being a good example. Sometimes, a case of a car failing to 'start' or something of that sort could be simply as a result of an electrical contact breakdown at the battery. Here all that is required in the name of auto electrical repairs is something as simple as filing the terminals that connect the car to its battery.
Vehicle charging systems haven't changed much over the last few decades. But with the increasing complexity of the modern automobile, along with the addition of many aftermarket accessories such as cell phones, DVD players, high-power audio systems, alarms etc., the role of the charging system is now more important than ever. The charging system on your vehicle can be thought of as a small power plant which does exactly what its name implies - charges and maintains a good state of charge on the battery.
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.
If your vehicle's engine misfires, hesitates, stalls, gets poor mileage, is hard to start or has failed an emissions test, it clearly needs something, though a tune-up in the traditional sense might not be the cure. If you tell a repair shop your vehicle needs a tune-up, the mechanic should ask what you feel the signs are that you need maintenance before recommending any service. Just like a doctor should ask what symptoms you're experiencing, a mechanic should seek to diagnose the problem. And just as a doctor may recommend some tests, a mechanic may do the same.