The battery is the first link in the chain of mechanisms which work together to provide cranking of the engine. In most modern vehicles, the battery is a lead-acid electrochemical device consisting of six 2 volt (2V) subsections connected in series so the unit is capable of producing approximately 12V of electrical pressure.
Each subsection (cell) consists of a series of positive and negative plates held a short distance apart in a solution of sulfuric acid and water. The two types of plates are of dissimilar metals. A chemical reaction takes place which produces current flow from the battery, when it's positive and negative terminals are connected to an electrical appliance such as a lamp or motor. The continued transfer of electrons would eventually convert the sulfuric acid in the electrolyte to water and make the two plates identical in chemical composition.
As electrical energy is removed from the battery, it's voltage output tends to drop. Thus, measuring battery voltage and battery electrolyte composition are two ways of checking the ability of the unit to supply power. During the starting of the engine, electrical energy is removed from the battery. However, if the charging circuit is in good condition and the operating conditions are normal, the power removed from the battery will be replaced by the alternator which will force electrons back into the battery, reversing the normal flow and restoring the battery to it's original chemical state.
Additional procedures covering basic testing and maintenance of the battery are covered in Routine Maintenance of this repair guide.
REMOVAL and INSTALLATION
See Figure 1
- Disconnect the negative battery terminal, then the positive battery terminal.
- Remove the battery hold-down retainer.
- Remove the battery from the vehicle.
- Inspect the battery, the cables and the battery carrier for damage.
- Install the battery in the vehicle and tighten the battery hold down retainer to 71 inch lbs.. (8 Nm).
- Install the negative batter cable, then the positive battery cable. Tighten terminal nuts to 11 ft. lbs.. (15 Nm).