No charge for bench testing your starter or alternator.
A starter is an electric motor used to start your diesel or gasoline engine
•When you turn the key in your vehicle's ignition, the engine turns over and then cranks. However, getting it to crank is actually much more involved than you might think. It requires a flow of air into the engine, which can only be achieved by creating suction (the engine does this when it turns over). If your engine isn’t turning, there’s no air. No air means that fuel can’t combust. The starter motor is responsible for turning the engine over during ignition and allowing everything else to happen.
An alternator is the device used to produce the electricity that a vehicle needs to run and to keep the battery charged.
•The battery is the heart of your electrical system. But you need something to keep the battery charged or it will lose its charge and die. This is the job of the alternator. The alternator produces electricity and delivers this electricity to the battery and maintains a full charge at all times.
•An alternator is part of the charging system that produces electricity for many devices. A type of generator, the alternator transforms mechanical energy into electrical energy. Although your car’s battery supplies some electricity, most of the electrical mechanisms within the vehicle, require the alternator’s steady stream of power.
Basically there are two types of lead acid batteries (along with 3 sub categories); The two main types are Starting (cranking), and Deep Cycle (marine/golf cart).
The starting battery (SLI starting lights ignition) is designed to deliver quick bursts of energy (such as starting engines) and therefore has a greater plate count. The plates are thinner and have somewhat different material composition.
The deep cycle battery has less instant energy, but greater long-term energy delivery. Deep cycle batteries have thicker plates and can survive a number of discharge cycles. Starting batteries should not be used for deep cycle applications because the thinner plates are more prone to warping and pitting when discharged.
AGM (absorbed glass mat) batteries function similar TO THE FLOODED, however they have one important design difference. AGM batteries have glass fibers woven into sheets that are put in between the plates of the battery. These plates are then soaked with battery acid. Rather than having acid sloshing around inside the battery, the acid soaked plates suspend the solution, and remain in contact with the plates at all times.