3 ways to boost your car battery

Posted 20 July, 2025 Andrew Rasch

When you start your engine, you usually take for granted that your battery will spring to life and help start your car.

But if you turn the key or push the start button and hear nothing, your heart sinks.

It’s often a sign of battery failure and you’re going nowhere until it’s recharged, repaired or replaced.

Batteries need care and attention, so we’ve compiled three ways you can make this important car part last longer.

1. Avoid temperature extremes

Car batteries rely on internal chemical reactions, which usually speed up in hot weather and slow down in the cold. Hot days increase fluid evaporation, which can damage the battery’s internal structure. The heat can also increase corrosion and lead to incorrect charging which reduces the battery’s longevity.

In cold weather, your battery’s capacity can drop, hindering its ability to start your engine. The cold can also thicken your engine oil, so the battery needs to work harder to get your car started. During cold weather the battery recharges at slower rates, meaning it may not be fully charged the next time you start your engine.

Solution: You can’t control the weather of course, but you can protect your car from the elements as much as possible. If possible, park your car in a carport or garage – especially overnight in winter – and if you’re out and about in the heat, look for a shady spot to park.

2. Keep your battery active

Batteries are designed to be used regularly, so avoid leaving your car unstarted for long periods. Even when the engine is off, batteries are susceptible to parasitic drain. That’s when electrical components such as interior and door lights, clocks, alarms and engine computers drain small amounts of power. Short trips might seem like the solution, but the alternator might not properly recharge the battery in the time it takes for you to duck down to the local shops.

Solution: If you can’t drive your vehicle for at least 30 minutes a week, use a suitable battery charger – available at RAA online or from an RAA patrol van. Keeping your battery fully charged will improve its longevity and hopefully avoid any premature issues.

3. Don’t neglect your battery

Like most things, your battery will deteriorate if you don’t look after it, especially as it ages and loses its ability to hold a charge. Over time, sulphuric acid in a neglected battery can cause corrosive material to form on the terminals and cables. The resulting green, flaky buildup looks awful and increases electrical resistance between the terminal and battery post, making the battery less efficient. Similarly, loose connections can prevent the battery from properly transmitting power.

Solution: If you’re having your car serviced regularly, your mechanic will update you on your battery’s health. But if not, or you service your car yourself, pay attention to the condition of the battery. Keep the terminals clean and make sure the battery is tightly secured to the mounting bracket and the connections aren’t loose.

If you’re experiencing battery issues, an RAA patrol van will come to you and perform a comprehensive system check. This includes cleaning the battery and tightening the terminals and battery post. To arrange this, call 131 111 or make a booking online. Best of all, RAA Plus and Premium members save $20 on RAA batteries.