Winter’s impact on car batteries: Top tips to keep yours running smoothly

As winter tightens its grip, your car battery faces its most challenging season. Dylan Petzer, vice-chairperson of the Tyre Equipment Parts Association (TEPA), has highlighted the increased risk of battery-related breakdowns during colder months.

Here’s a closer look at why batteries struggle in winter and how you can keep yours performing reliably.

Why cold weather is hard on car batteries

Chemical slowdown: Car batteries rely on chemical reactions to generate power. As temperatures drop, these reactions slow down, reducing the battery’s ability to deliver the current needed to start the engine.

Freezing weather can drain a car battery by 30% to 60% of its capacity, meaning even a healthy battery might falter.

Increased internal resistance: Cold temperatures raise a battery’s internal resistance, making it harder to supply power.

Thicker engine oil in winter adds to the strain, as it requires more energy to turn over the engine.

Reduced charging efficiency: Not only does a battery deliver less power in cold weather, but the alternator also recharges it more slowly.

Frequent short trips, which don’t give the alternator time to replenish the battery, can lead to a drained battery.

Petzer says there are clear signs a battery may be on the verge of failure:

“Watch for slow engine cranking, dim headlights that brighten when revving, and clicking or grinding sounds when turning the key,” he explained.

He also advised looking out for the following:

• Corrosion on the terminals (white, powdery deposits)

• A swollen or misshapen battery case (can indicate freezing or overcharging)

• The dashboard battery warning light coming on

• Eight expert tips to avoid winter battery failure

TEPA members, including First Battery Centre, offer the following advice to keep your battery in top shape:

• Test your battery regularly: Especially if it is over three years old. Many fitment centres offer free testing. Replace a weak battery before it fails.

• Clean battery terminals: Corrosion can prevent current flow. Use a baking soda and water mix to clean the terminals and ensure connections are tight.

• Keep the battery warm: Park in a garage if possible or use an insulation blanket. In colder regions, consider a battery warmer.

• Limit short trips: Combine errands or take longer drives to give the alternator enough time to recharge the battery.

• Switch off electronics: Turn off lights, heaters and accessories before starting the engine, and ensure everything is off before parking overnight.

• Check the charging system: Have the alternator, starter and overall charging system checked, as cold weather affects these too.

• Change the engine oil: Fresh oil flows more easily, reducing the load on your battery during start-up.

• Invest in a quality charger: A smart charger is ideal for vehicles left unused for long periods, maintaining charge and prolonging battery life.

Even with proper care, car batteries typically last three to five years.

“If your battery is nearing the end of its lifespan, especially if it’s already showing signs of weakness, don’t wait for it to fail,” Petzer concluded. “Regular checks and a little extra attention in winter can go a long way in keeping your vehicle reliable throughout the season.”