Contents: Examination ⇊ Replacement ⇊
Examination
1. Disconnect both wires from the battery.
Caution! The negative cable should always be disconnected first and reconnected last. If the car stereo system is equipped with a security code, make sure you have the correct combination to activate the system before disconnecting the battery!
2. Check the electrolyte level in the battery (only applies to batteries that require maintenance and are equipped with removable covers) – the electrolyte should completely cover the lamellas, otherwise the appropriate amount of distilled water should be added to the jars. DO NOT OVERFILL – excess electrolyte will start to spill over the edges of the necks when the battery is overcharged! Using a hydrometer (ask in car accessories stores) measure the specific gravity of the electrolyte (see accompanying illustration). Remove the caps from the filler necks and take a sample of electrolyte from each of the battery jars in turn with a hydrometer. Following the manufacturer's instructions, determine the specific gravity of the electrolyte by the position of the measuring float of the device. At a normal charge level, the specific gravity of the electrolyte should be 1.270 units (green zone of the measuring scale). When the electrolyte density is too low (red zone of the scale) the battery should be charged (see Chapter Routine maintenance). The battery output voltage should be 12.6V or slightly higher.
Note: The nominal value of the electrolyte density is determined depending on the ambient temperature (and is directly proportional to it) – use the temperature map supplied by the manufacturer with the battery.
3. A more accurate check of the battery condition can be made using a universal meter (ask in car accessories stores). The device allows you to determine the battery's ability to conduct the starter and supply power to on-board consumers of electricity under increased loads on the engine. Connect the meter to the battery terminals (see accompanying illustration). Follow the device manufacturer's instructions - when the load is turned on for 15 seconds, the battery voltage should not drop below 9.6 V, otherwise the battery must be replaced.
Note: At ambient temperatures below 0°C, the minimum acceptable reading is reduced to 9.1 V.
Replacement
1. Disconnect both wires from the battery.
Caution! The negative cable should always be disconnected first and reconnected last. If the car stereo system is equipped with a security code, make sure you have the correct combination to activate the system before disconnecting the battery!
2. Release the fastener and remove the battery mounting clamp on the tray (see accompanying illustration).
3. Remove the battery from the tray (see accompanying illustration).
Note: Special brackets with a handle are available. Using such a bracket significantly simplifies the procedure for removing the battery from the engine compartment.
4. Remove the pan and carefully inspect it for signs of corrosion.
5. If necessary, remove the pallet support in order to remove corrosion products from underneath it and to apply appropriate protective treatment to the metal (use zinc based primers).
6. When replacing, make sure that the replacement battery meets the characteristics of your vehicle.
7. Installation is carried out in reverse order.