Before attempting to disconnect and reconnecting the battery from the vehicle, ensure all electrical equipment is turned off including the ignition system, air-conditioning, lights and radio. Remove the keys from the ignition and if the vehicle has a Frequency Operated Button (FOB) with keyless entry, the FOB should be kept at least 2 metres clear of the vehicle.
In vehicles that have a computerised electrical system, disconnecting the battery may erase memory from the engine control module (ECM), transmission control module (TCM), clock, radio, security codes and navigation systems. A battery backup can be used to retain memory by plugging a power source into the cigarette lighter socket, OBD (On Board Diagnostic) plug or using jumper leads on the positive terminal lead and earthed to the vehicle body.
If you need to reset the battery management system (BMS), FOB or Idle Stop Start (ISS) system in the case of the warning below, the drivability of the vehicle will be restored after completing at least one drive cycle. The drive cycle is usually defined in your vehicle manual.
Always read the battery health and safety procedures before new battery installation.
Vehicles that have BMS, FOB’s and ISS functionality may need to be powered down by disconnecting the battery to reset the system and prevent damage to the vehicle and new battery.
Before disconnecting the battery from a vehicle fitted with an ISS system, the battery monitoring sensor will need to be disconnected from the battery earth lead.
Battery backups or battery chargers must not be connected directly to the battery sensor terminal as this can cause damage to the sensor. The earth lead should always be earthed to the engine block or vehicle body.
NOTE: When possible always refer to the vehicle’s user manual.
SAFETY PRECAUTIONS FOR VEHICLES FITTED WITH AIR BAGS
Removal or replacement of battery connections will not unintentionally trigger an air bag system. However removal of battery connections with the ignition remaining “ON” can cause damage to electronic components including the airbag system – always check to ensure the ignition is “OFF” before removing either battery terminal.
Before carrying out any work on the electrical system beyond the battery, the air bag system must be electrically disabled. Never indiscriminately probe the electrical wiring/connectors in the vicinity of the steering column.
The wiring and harness connectors of most air bag systems are bright yellow; do not interfere with any harness of this colour. As an added safety measure it is recommended that no person should remain seated behind the steering wheel while any electrical service work is carried out on the vehicle.
Removal of Old Battery
- Note the location of positive terminal and mark polarity on positive cable.
- Remove the negative (-) terminal first. This precaution is necessary to avoid damage to wiring and the battery by accidentally grounding tools.
- Remove the positive (+) terminal.
- Undo hold down clamp and remove the battery from the vehicle
New Battery installation
- Check battery height to ensure there is sufficient bonnet clearance.
- Inspect tray and area for corrosion. If necessary, scrub the area with a water and baking soda mix and rinse with water.
- Corroded steel parts should be dried and painted with acid proof paint. Terminals should be cleaned and brushed.
- Cable and starter motor connections should be checked and tightened if necessary.
- If terminal clamps or cables are badly corroded, they should be replaced.
- Place the new battery in the tray, ensuring it sits level and that terminal posts are positioned same as the battery.
- Place and tighten the hold downs securely so that the battery cannot move in the tray.
- Apply a thin coating of high temperature grease to the posts and cable connections.
- Replace cables, ensuring positive cable is first followed by the negative. Tighten connections. Note: Do not over tighten.
- Never hammer cable connections onto battery posts, as this can damage the battery posts and cover.