A battery cannot be accurately tested until it is at or near a fully charged state. Disconnect the negative battery cable and perform the following tests: visually inspect the indicator eye on the battery; if dark, charge the battery. For batteries with removable caps, check the electrolyte level, ensuring it is above the plates, and add distilled water if low, avoiding overfilling. Test the specific gravity of the electrolyte with a hydrometer, aiming for approximately 1.270 at 68-degrees F. For the open circuit voltage test, connect a digital voltmeter to the battery terminals; a fully charged battery should read about 12.5 volts. An accurate battery load test requires a load tester, which evaluates the battery's ability to handle heavy amperage draw; maintain the load for 15 seconds, ensuring the voltage does not drop below 9.6 volts. For the battery drain test, ensure all accessories are off, then connect a digital ammeter to check for a drain; a normal drain is around 100 milliamps, while excessive drain indicates a problem. When replacing the battery, always disconnect the ground cable first, then the positive cable, and isolate the cable ends. Remove the battery heat shield and hold-down clamp, then lift out the battery carefully. Inspect the battery tray for corrosion and clean it if necessary. If replacing the battery, ensure the new one matches the original specifications. Installation follows the reverse order of removal, and after connecting the cables, apply a light coating of petroleum jelly or grease to prevent corrosion.
