Battery replacement

Removing and installing the battery is done when it is necessary to clean, check its condition, or replace it with a new one. The service technician should follow the established procedure when replacing the battery.

Some vehicles are sensitive to battery discharge because certain electronic systems remain without power and can lose stored adaptive values. Check manufacturer and owner information to determine which electronic systems will be affected by the loss of power. You must identify each system that requires security or initialization codes to be reset and ensure that procedures and equipment are available to reinitialize the system or module. When necessary, an external 12 V power source is used via the diagnostic socket using a separate cable or via the cigarette lighter socket if it is permanently on. Only after connecting the external power supply can you start disconnecting the battery.

When disconnecting the battery terminals, always remove the negative terminal first. After removing the negative terminal, if the key touches the chassis when it is on the positive terminal, there will be no spark because there is no connection to the negative terminal. After all, the chassis is no longer at ground potential. You still have to be careful not to bridge the key directly from the positive to the negative terminal, as this could cause a large spark.

The spring-loaded terminals are removed by lifting the lever which spreads the terminal and frees it for removal from the battery post. These are the so-called quick terminals for quick interruption of the power supply due to a major breakdown in the vehicle.

For terminals tightened with nuts and bolts, loosen the nut with an open-end wrench. Using regular pliers or an open-end wrench can cause problems. These tools can slip out under more pressure, breaking the cell cover or damaging the case. Always hold the cable while loosening the nut, as this reduces the pressure on the battery post, which could break. If the terminal does not lift easily from the post when released, use a puller. Lifting the terminal with a screwdriver or a bar loads the pole and the base. Doing so can break the cell cover or crack the pole.

Mounting the battery on the vehicle is done in reverse order. The battery is carefully placed in the holder, covered with heat shields, and secured with hold-downs. Terminals are additionally opened so that they can be easily placed over the posts. First, the plus terminal is installed and tightened. Then the minus terminal is installed and tightened. Terminals are coated with anti-corrosion paste or spray. If present, the external power source that stored the adaptive memories of the electronic devices on the vehicle is turned off.

Batteries can look lighter than they are. Always lift them carefully and get help if necessary. When reconnecting the battery, be sure to connect it correctly. If you reverse the polarity, the current flows in the electrical system in the opposite direction. Reverse polarity is likely to damage some or all of the electronic control units throughout the vehicle, so what started as a simple maintenance task becomes an expensive diagnostic and repair job to compensate for the damage.