Check your car battery’s health

• Car batteries naturally lose charge – the longer you leave your car without driving it, the more likely that your car battery is going to be flat. Over time, a battery will slowly drain power and if it drains too much, it won't have the charge to start.  

• Leaving electrics on – components like headlights and internal cabin lights when not in the car will drain your battery. Additionally, if sitting in your car idle with the engine off, items like phone chargers, sat navs, and dash cams will draw power directly from the battery. Doing this for long periods of time will drain the charge.  

• Short journeys – if you only drive short journeys, the battery cannot retrieve a full charge, reducing its ability to hold a charge and shortening its lifespan over time. 

• Dirt and grim – dirt and grime on the battery terminals can cause issues, preventing your battery from transferring power efficiently.  
  
  

• Speeds up wear – high temperatures accelerate the chemical reaction inside the battery, which causes internal parts to degrade faster.  

• Fluid evaporation – heat evaporates the water in the electrolytes, leaving plates exposed and prone to damage. 

• Hidden weakness – a battery can seem fine in the summer, but the heat damage means it may fail late, normally when the cold weather arrives.  
  
  

• Reduced power output – cold temperatures slow down the chemical reactions inside the battery, meaning it produces less energy. 

• Harder engine starts – oil thickens in the cold, so the starter motor needs more energy – just as the weakened battery provides less. 

• Exposes summer damages – a battery weakened by heat is far more likely to fail suddenly in freezing conditions. 

• Summer heat accelerates chemical processes, causing more long-term damage.  

• Winter weather reduces battery performance and forces your battery to work harder.  

1. Checking the voltage with a voltmeter 
   Before starting, switch off the ignition and make sure that all car accessories that could drain the battery, including the air conditioning, headlights and car radio are turned off. Carefully remove the covers on the battery terminals and connect the positive end side of the voltmeter to the positive (red) terminal first. Then connect the negative side to the voltmeter to the negative (black) terminal. 
    
   Now, check your reading. A healthy battery should read between 12.4V and 12.7V. A reading of just under — like 12.3V — can indicate your battery is only 75% charged. 
    

2. Try the headlight test 
   While the headlight test isn't the most accurate test, it can sometimes be a good indicator that something is wrong before you even look at the battery. Just turn your headlights on and check to see whether they look darker than they should be. If that is the case, your battery may be low.  
    
   Additionally, you can put your foot on the accelerator lightly; if your headlights get brighter, it might mean that there is a fault with the alternator, which is unable to supply enough current to the battery. Headlights should stay at the same level when revving the car. 
    

3. Battery health indicator 
   Many modern cars come with batteries that have an in-built battery health indicator. These indicators will have some kind of arrow that turns either red or green depending on the state of the battery. Red indicates low voltage and green indicates good condition. 

4. Physical check 
   You can often spot the warning signs of a failing battery with a quick visual check.
   
   While it’s still in the engine bay, shine a torch over the battery and look for corrosion around the terminals. A strong sulphur smell, bubbling, or dried liquid are all red flags — if you notice any of these, it’s time to replace your battery.
    
   For a closer look, you can safely remove the battery (negative/black terminal first, positive/red terminal last). Once out, check the casing carefully. Bulges suggest overcharging, and any cracks or leaks mean the battery needs replacing straight away. 

   Don’t risk being caught out with a flat battery — if you spot any of these signs, visit your nearest Autoparts store branch for a replacement or shop here. 

Don’t risk being caught out with a flat battery — if you spot any of these signs, visit your nearest Autoparts store branch for a replacement or shop here. 

• Keep your battery terminals clean – Dirt and corrosion can interrupt the flow of power. Use a brush and a baking soda solution to clean them, or shop online or ask in store for cleaning products that make the job easier.  

• Check connections are tight – Loose connectors put extra strain on the battery.
  

• Carry out regular inspections – A quick check can stop small issues turning into costly breakdowns. Our team can test your battery in minutes.
  

• Run your engine regularly – If your car isn’t used often, starting it up and letting it run helps keep the battery charged.
  

• Protect against the cold – Cold mornings are tough on batteries. A battery cover or trickle charger can help prevent problems.
  

• Consider your driving habits – Avoid only short journeys or frequent night-time driving in winter if possible.
  

• Know your battery’s age – Most last 5–7 years. After that, replacement is often the most reliable option, especially before the cold weather sets in.