- To supply power to the starter and ignition system so the engine can be cranked and started.
- Supply the extra power necessary when the vehicle’s electrical load requirements exceed the supply from the charging system.
- Act as a voltage stabiliser in the electrical system. The battery smooths out or reduces high voltages which can occur in the vehicle’s electrical system. These excessively high voltages would damage other components in the electrical system if it were not for the protection provided by the battery.
- As a battery reaches the end of its useful operational life, typical failure modes such as grid corrosion and positive plate disintegration takes place causing the battery to lose capacity and its ability to start the engine.
- Premature battery failure can have many causes, such as under orovercharging, vibration damage due to a loose battery hold down clamp, or even contamination of the electrolyte.
- Poor maintenance of the battery and vehicle electrical system usually results in early battery failure.
- How do I look after my battery?
- Make sure the vehicle voltage regulator is set correctly to specification, usually between 13.8 and 14.2 volts for low maintenance battery types.
- Add approved battery grade water to cover the plates by 10-15 mm.
- Ensure the battery is kept clean and dry, and that the posts, terminals and cables are covered with a thin layer of petroleum jelly to protect against corrosion.
- All lead-acid batteries will naturally self-discharge which can result in loss of capacity from sulfation.
- Heat speeds up this self-discharge, so that is why it in not a good idea to store batteries in a hot garage or warehouse.
- The rate of self-discharge is most influenced by the temperature of the battery’s electrolyte and the chemistry of the plates.
- This self-discharge is often mistaken for concrete floor causing the battery to drain. Some experts believe that storing car or deep cycle batteries on a colder concrete floor might actually slow down the self-discharge (leakage) rate because the floor acts as a heat sink and cools the battery.
- There are a number of factors affecting a vehicle charging system’s ability to recharge a battery, such as how much power and charging voltage from the alternator is diverted to the battery, how long the power is available, and the temperature.
- Idling the engine or short stop-and-go trips during bad weather or at night will not fully recharge a car battery. It will leave your battery undercharged which causes sulfation.
- When a dead battery needs to be recharged, it is best to use an external battery charger because you could overheat and damage your vehicle’s charging system and you will save a lot of fuel and wear and tear on your engine.
- Lead-acid batteries can be a source of fuel for external explosions or explode internally.
- Charging a wet lead-acid battery produces hydrogen and oxygen gasses as electrolysis of the water occurs. That is why charging needs to occur in well ventilated areas.
- While spark retarding vent caps help prevent external battery explosions, a spark can occur when jumping, connecting or disconnecting charger or battery cables and ignite the gas causing an explosion.
- Less common internal explosions usually occur while starting the engine or if the battery is rapidly heated from a short circuit or fire.
- Normally, an internal battery explosion will blow the filler caps or case cover off the battery and splatter electrolyte all over the engine compartment or battery box.
- Another source of internal battery explosions is caused from a direct electrical short across the battery’s terminals. The battery rapidly over heats from the high current and can explode.
- The largest numbers of internal battery explosions occur in hot climates due to the loss of water in wet “maintenance free” and low maintenance starting batteries.
- Most internal battery explosions could have been prevented if the plates were always covered with electrolyte.
- A bad or weak starting battery causes additional stress on a charging system, starter motor or starter solenoid.
- It can cause premature failures due to compensating for the voltage or current.
- If you replace a battery, alternator, voltage regulator or starter, you should test the other components for damage and repair or replace them as required.
- Use only distilled, deionized or demineralized water to replace the lost water in batteries.
- This is because using tap or reverse osmosis water from residential systems can produce calcium or magnesium sulfate crystals that can fill the pores and coat the plates.
- Wet batteries will have a longer service life if you do not use tap water.
- If the plates are not covered and distilled water is not available, use rain or tap water to prevent sulfation and internal battery explosions.
- Car batteries last an average of two thirds as long in hot climates compared to cold climates due to increased grid corrosion and water loss.
- Heat kills batteries, especially sealed wet “Maintenance Free” (Ca/Ca) batteries, and cold reduces the battery’s starting performance.
- A starter motor will only use a fixed amount of current from the battery, based on the resistance of the motor.
- A higher Cold Cranking (CCA) performance or greater Reserve Capacity (RC) or Amp Hour (AH) capacity battery supplies only what is required.
- This will not damage your vehicle; however, using batteries with higher or lower voltage or physically too high could potentially cause harm. For example, using a six-volt or 24-volt battery in a 12-volt vehicle electrical system.