Car Care

Don’t let your battery get the better of you this winter

Battery care is a subject many don’t give a second thought – until the day you crank the key with disappointment. You find yourself scrabbling around looking for a set of jump leads and someone to give you a much needed jump start, or worst case scenario, you’re stuck at the supermarket carpark while it’s pouring down, having to call the AA for help.

jumper cables to battery

Extreme winter temperatures can affect the performance of your car battery, depending on the age and state of health. While we cannot change the temperature, we can prepare and minimise the risk of winter causing motoring headaches.  That’s why it pays to get in early as we head into the winter months, to avoid the common hazards winter places on the car battery.

Lead acid automotive batteries

Lead acid automotive batteries are consumable items and are bound to fail as it reaches its use by date (end of life).  Taking good care of your battery by keeping it in a 100% state of charge, making sure that the charging system of the vehicle is operating as per requirement of the battery and there is no parasitic drain on the battery, helps to extend the battery life.

Watch your battery load

We are only human, and there may be occasions when you accidentally abuse the battery by leaving loads (lights, radio etc.) on overnight. This will not kill your battery but will drain all stored energy in the battery and in some instances can shorten its life. If this does happen you should get the battery fully charged using a seven-stage battery charger (smart charger) as soon as possible. This is crucial as modern calcium batteries (flooded, sealed, AGM, EFB) will not recover to 100% state of health from the charge received from the alternator. Alternators are not designed to recharge flat batteries.

The inner workings of an automotive battery

Lead acid batteries have been around for decades and are found in the majority of vehicles on our roads.  These batteries have a plastic case that houses a series of lead plates immersed in a pool of electrolyte – a mix of water and sulphuric acid.

The lead acid battery doesn't produce a charge. It receives and stores an initial charge through a chemical reaction between the cell’s lead plates and the electrolyte. It stores this chemical energy to be given off as electrical energy when and as needed.

If a battery is deprived of charge, the positive and negative lead plates are slowly coated with sulphur to chemically change the lead plates to lead sulphate – a process known as sulphating.

Sulphation reduces the surface for chemical reaction on plates and density of the electrolyte.  When this happens, the capacity of the battery drops and it can also actually lose charge.

If batteries are left too long without a fresh charge, they can discharge beyond the point of recovery. 

So why do batteries fail more in winter? 

Extreme hot and cold weather conditions can increase the rate of discharge. Colder temperatures play havoc on lead acid battery electrolyte, causing it to freeze or thicken, which slows the chemical reaction.

A fully charged battery will be less affected by the cold weather because the electrolyte concentration is higher. A cold engine with thicker oil can also put extra strain on the battery, demanding more power to start the car.

It is in winter that older batteries, which would have not failed otherwise, tend to fail as they have to work even harder to crank the motor.

car battery

Keep your battery in top shape with these five tips:

1) Get your battery checked and tested before winter hits

If your battery is at the end of its serviceable life, it is better to find out while you have time on your hands than to be stressed when your car does not start on the day you have a very important scheduled appointment.

Prepare yourself by getting your battery checked and tested before it refuses to start your car.  AA Battery Service can come to you in the comfort of your home to check and test your car battery.

Have multiple cars? No problem, they will attend to all of them. The initial check will cover:

  • Looking at the condition of all connections
  • Looking for signs of corrosion
  • Checking the battery mounting
  • Checking the battery’s physical condition

The battery will then be tested using a state–of-the-art battery tester to analyse the state of health of the battery and the charging system of your car. There is nothing better than starting winter with a healthy battery and peace-of-mind that your car will start every time.

2) Park your car in a garage where possible

Now that you know that your battery has been tested and replaced (if warranted), look after it. Keeping your vehicle in a garage when it’s not being used will protect it from the cold. Starting it will be a lot easier, putting less strain on the battery.

Don’t have a garage park facing away from the elements? Park close to your house if possible. Cold weather affects the state of health of the battery causing it to lose its charge faster.

3) Allow the battery to ’juice up’ before and after use of the car

The key to getting the optimum performance out of your lead acid car battery is to keep it ’juiced up’ (100% state of charge). If your car is not used daily and driven for a reasonable distance, ensure when you start the car in the morning that you give it some time before you turn on your heater, radio, wipers, lights etc.

When turning your car off at the end of the day, turn off all auxiliary, phone charger, lights, wiper, radio and any load that drains the battery. Give it a few minutes before turning the engine off. This will help to top up your battery so it’s ready to get your car going the next morning.

If you’re not using your car regularly or for short drives only, your battery may fail to receive enough charge to replace what was being used. You may need the help of a maintenance charger to keep the battery topped up to 100% state of charge. This will not only help to start your car every time you need it but give your battery a longer life.

4) Keep your battery and all connections clean and in a good state of repair

A battery that is clean and has clean connections will have a longer life. Cleaning your battery cables and terminals regularly will prevent corrosion build up. If you already have corrosion on your battery, it can easily be removed with warm water, baking soda (if available) and a wire brush (make sure you wear eye and skin protection).

Once the terminals are clean, be sure to wipe with a cloth and water and check that all connections are tight. This process ensures that there is minimum resistance for the battery to receive and dispense charge.

For newer vehicles it is recommended that you do not remove the battery terminal without a memory minder. Get a professional at an AA Auto Centre to do that for you.

5) Listen for early warning sounds

Having taken care of all of the above and realising that you still have a battery that is aged (more than 5 years) it is important that you watch for the tell-tale signs of a weak battery.

One of the most common signs of a weak battery is a slow cranking when you start the car. If the car battery is too weak to provide sufficient voltage to the starter, you'll hear a distinctive clicking sound and the engine won't crank over. The clicking could indicate that the battery is not fully charged or has passed its serviceable life. This provides a starting point for further diagnosis.

Get a battery specialist. Remember to not force a weak battery by continuing to crank the engine. This can damage your starter motor, which can end in an expensive repair.

Batteries crop101

We have 40 AA Auto Centres around New Zealand that stock AA Batteries. Click here to find out where your nearest AA Auto Centre is situated, and get in touch - our team will be happy to help.

Battery chargers can also be purchased online at AA Shop. Click here to learn more. 

If you would like to replace your vehicle's battery before winter, click here to book an appointment at your nearest AA Auto Centre.

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