General Information
Battery Construction:

The battery stores, stabilizes, and produces electrical current to operate various electrical systems in the vehicle. A batteries ability to accept a charge and produce high-amperage current output over an extended period determines whether a battery is good or bad.
The ability of the battery to store electrical current comes from a chemical reaction between the sulfuric acid solution (electrolyte) and the lead +/- plates in each cell of the battery. As the battery discharges, the plates collect the acid from the electrolyte. When the charging system charges the battery, the acid is forced out of the plates into the electrolyte.
The amount of acid (specific gravity) in the electrolyte can be measured with a hydrometer. The factory installed battery is equipped with a built-in hydrometer (test indicator) to assist in determining the state-of-charge. The factory installed battery is also nonrefillable, water can not be added. The battery is vented to release gases that are created when the battery is being charged. The battery top, posts, and terminals should be cleaned when other underhood maintenance is performed.
WARNING: Do not attempt to assist boost, charge, or test battery when electrolyte level is below the top of the plates (yellow or bright color dot is visible). Personal injury may occur.
When the electrolyte level is below the top of the plates (yellow or bright color indicator dot), the battery must be replaced. The battery must be completely charged (green dot) and the top, posts, and terminals should be properly cleaned before diagnostic procedures are performed.