Battery Cycle Life
If you take a fully charged battery, discharge it and then recharge it, you have completed a cycle. The cycle life of a battery is how many times you may complete this process. You may discharge a battery to varying depths, different batteries are designed to withstand different amounts of cycles and depths of discharge.
Starter batteries for cars, trucks or plant vehicles are generally built to supply a lot of power for a short period of time whilst starting an engine. Batteries for forklift trucks may be significantly flattened over an eight hour shift. Both batteries could be of the same power, but one is more like a sprint runner, while the other is like a marathon runner.
Since the advent of the start stop engine in modern day cars, the old-fashioned starter battery has been replaced with a battery that is closer to the forklift truck battery. One of the biggest drains with a modern stop start engine is the power needed to drive the alternator. In an attempt to increase fuel economy of these vehicles, manufacturers have used a number of methods to make the charging of the battery more efficient therefore using the alternator less.
Driving down the road the engine management system detects that the battery is fully charged so switches off the alternator to save fuel. When the cars brakes are applied, the energy from them is harvested and pushed into the battery, when the engine management system detects the battery is in a discharge state then the alternator starts up and a high rate of charge is transferred into the battery, as you can guess this is all stress applied to the battery. Because of these advances in technology of the vehicle, the batteries have become more resilient. There are two types currently available; these are EFB enhanced flooded batteries or AGM (Absorbent Glass Mat) batteries.