Car battery care

How long does a car battery last?

Generally, in New Zealand conditions provided the battery is maintained, the fitment is correct for the vehicle and the battery is kept at 100% state of charge, it is expected to last 3-5 years.  In saying that, the life you get out of your battery is very dependent on you. All vehicles come with OEM battery fitment specification. You must ensure that your next battery meets or exceeds the OEM recommendation. 

• Check the cranking amps (CCA rating), that is the ability to crank the motor.  Batteries with high cranking amps do not get stressed and over worked and hence will perform at optimum for a longer period.  See that the battery has the required capacity (AH).  Ensure that AH rating meets the OEM specification too. When the vehicle is off your car battery is still keeping all computers going.  A low AH rating will not be able to maintain consistent power supply for all computers in the vehicle. Modern vehicles come with many computer systems.  Installing an incorrect battery will die prematurely, cause malfunction and affect vehicle performance and electrical issues.

• Most batteries now come as maintenance-free but you still need to maintain the connections and state of charge.  Failing to keep the battery to 100% state of charge is the largest factor that affects battery durability and longevity.  If you are not using your car on regular basis invest in a maintenance charger (smart charger) to help you to keep the battery topped up for next time you need to use the vehicle. 

Winter battery care

At colder temperatures, a battery’s ability to provide enough power to start and run a vehicle is reduced. Starting an engine can also take up more current than needed under normal conditions. As the battery runs down it quickly reaches the point where it can’t deliver enough current to keep up with the demand.

• Keeping your battery charged - If the car is not driven daily for a reasonable distance, ensure when you start the car in the morning give it some time before you turn on your heater, radio, wipers, lights etc. When turning the car off at the end of the day, turn off all auxiliary, phone charger, lights, wiper, radio and any load that drains the battery.

• Park your car in a garage where possible - If you can, park your car in a garage or under cover to keep it out of the cold. Avoid parking on the lawn as condensation can collect on the engine and ignition parts which can cause current leakage. 

• Keep battery and connections clean - Clean the top of the battery and the terminals with a cloth every so often. Grease and dirt buildup can drain your battery’s power. Routinely examine the battery for dirt and immediately remove any buildup. Keep an eye out for sulfation around the terminals. Check that your mechanic cleans the battery terminals during your car’s servicing to keep the connection in good working order.

• Use a Battery Charger - We recommend regular recharging of your battery with the Smart Charge that can be left connected to your vehicle's battery maintaining a full charge on a healthy battery while the vehicle is not being used.

If your battery is more than three years old, a typical sign that it’s failing is your car cranking slowly when you attempt to start it. It might be time to consider getting your battery tested and replace it if your car becomes sluggish to start, particularly on cold mornings, rather than risk being stranded. Get AA Battery Service to test your battery and related electrical system to ensure the state of health of your car battery is good and reliable.

Summer battery care

Summer heat can be more damaging to your car’s battery than the snow and cold of winter. Excessive heat causes the fluid in your battery to evaporate, weakening the battery’s charge and causing plate corrosion. This eventually leads to sulfation (crystals forming on the battery’s plates), which will eventually make your battery unusable.

• Watch for corrosion - Increased heat can cause corrosion inside your battery which can result in inhibited current flow. Inspect your battery on a regular basis for signs of corrosion. Clean any corrosion with a copper brush or a scouring pad.
• Check the water level - In a lead-acid battery, the summer heat can cause the water to evaporate from the electrolyte. Check the water level in each cell and if low, refill with distilled water.
• Keep it clean (See winter care above)
• Keeping your battery charged (See winter care above)
• Park your car in a garage where possible (See winter care above)
• Use a Charger (See winter care above)

Battery care when car is not used for a long time

All batteries have a natural tendency to go flat over time when not used. Lead Acid batteries (automotive batteries) lose charge over time particularly when not used for extended period. The rate of discharge on the battery depends on the battery’s age and the electrical devices in your car that use energy to maintain memory and settings while the car is parked.

A suitable maintenance charger will always keep your battery fully charged. The charger will automatically turn on as the charge in the battery drops below required voltage. It will not damage or over charge your battery. AA Roadside technicians can help to recommend and install a maintenance charger as they carry these with them for your convenience.

Important: Get professional advice from your automotive dealer or an automotive technician.

It is not a good idea to disconnect the battery terminal in a vehicle. Most modern vehicles run on several modules (microcomputers) to maintain memory and settings and need a consistent supply of power. In many instances, once you lose this, you will need the dealer to reset / programme the settings.