Top Tips for Maintaining Your Car Battery
FixMyCar offers some maintenance tips to keep your car battery fully-charged and functioning for longer.
Book a car repair nowEllie Dyer-Brown
Tuesday February 27 2024
5 min read
Your car battery is hidden away, which makes it easy to forget about. There's a reason that the saying "out of sight, out of mind" is so famous. But did you know that there are ways you can extend its lifespan?
This guide discusses our top tips for getting the most out of your car battery.
1. Perform a visual inspection
Before you set off in your car, take a minute to lift the bonnet and carry out a visual inspection. There’s no need to remove the battery - simply see if you can spot any signs of damage, corrosion or dirt. You should also ensure there are no obvious blockages in the open vent or pipe if it has one.
2. Clean your battery
Even if you stick to the four-year replacement guideline, dirt and debris will inevitably build up over this period and begin to corrode metal components such as the battery terminals.
We recommend cleaning your battery every couple of months to prevent damage. You can make a cleaning solution using baking soda and water or buy a pre-made one. A wire brush is the best tool for removing dirt.
3. Drive regularly
When you use your car, the alternator kicks in and tops up the battery's charge, which is why regular driving is crucial. This is one of the simplest things you can do to maintain your battery's health, and it's even better if you can fit a longer drive in (30 minutes once a week should be enough).
Here are five signs of a faulty alternator.
4. Avoid too many short journeys
Using your car for many short journeys puts extra strain on the battery because it doesn't have time to recharge fully. Do this often enough, and eventually, you will have a flat battery. Short trips are fine if you go on a longer drive once a week.
If you need a new battery fitting, FixMyCar can help you find the right garage at the right price.
5. Invest in a battery charger
This tip mainly applies if you use your car infrequently (for instance, if you have a classic car that you only drive a few times a year).
Battery chargers can differ in how they function:
Maintenance chargers allow ‘trickle charging’, designed to send a small amount of electricity to your battery to keep it healthy during longer periods when it isn’t being used.
Engine start chargers do a job similar to jump-starting your car. This takes a lot of energy and requires a heavy-duty charger.
Conventional chargers take six to 24 hours to recharge a flat battery fully.
Find out how to charge a car battery in this guide.
6. Maintain your battery’s water level
Electricity and water don't usually go together - but they do in lead-acid batteries. A mixture of water and sulphuric acid sits inside the unit between the terminals, evaporating over time. When you inspect your battery, the plates should be fully covered - if they are exposed, the fluid level is too low.
Always use distilled water to top up the fluid; tap water contains minerals that can harm your battery’s lifespan. Ionised water is best for performance.
7. Check your battery’s acid level
It’s a good idea to check your battery’s acid level at the same time as the water level - both need to be done roughly every six months.
When car batteries are constantly undercharged at a percentage less than 80, this is called acid stratification. It means that electrolytes concentrate at the bottom and leave the upper half of the battery starved, causing damage. If you don't feel confident checking your battery, a mechanic will gladly do it for you.
8. Make sure the battery is secure
Batteries are often secured in place with metal straps. If they are too loose or missing, the battery will rattle around due to the engine's vibrations, which could cause damage. You can use a torque wrench to tighten them slightly, but avoid doing this with too much force, or you might accidentally crack the battery casing.
9. Consider battery storage
The battery will be drained after months without use. Instead of leaving it in an unused vehicle, consider putting your battery in storage. Once removed from the car, it will need charging roughly once every three months.
10. Check for parasitic drains
A parasitic drain is an electrical component that uses electricity when it shouldn't, repeatedly causing the battery to go flat without an apparent cause. This problem is more common in older cars and is often caused by poor earth connections.
You can check for a parasitic drain using a cheap multimeter. Attach it to the battery with the engine switched off; if you see the voltage decrease, there's probably a component using electricity.
11. Replace every four years
Unfortunately, car batteries don’t last forever - it’s recommended that they should be changed every four years. By sticking to this schedule, you can rest assured that your battery is likely in good health for the duration of its use.
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Ellie is FixMyCar's Content Manager. She has over three years of experience writing about cars and regularly collaborates with automotive experts to provide trustworthy advice for drivers that is easy understand. Her work has been featured in Yahoo! Finance, iNews, The Daily Express and The Sun. She has a BA in English literature and an MA in creative writing from Durham University. Outside of work, Ellie follows F1 and eagerly awaits Ferrari's next era of dominance in the sport. She drives a Suzuki Swift.