Knowing how to charge a car battery is crucial for both your safety and the maintenance of your vehicle. If you’ve been wondering how to connect a car battery charger or you just don’t know where to start when it comes to recharging a flat or weakened car battery at home – we have the perfect guide for you.
Read on for all the answers you need to get back on track, and back on the road.
Recharging a car battery at home doesn’t have to be complicated - it’s easy to do as long as you have the right equipment. You’ll need protective gloves (and glasses if you feel they’re necessary), a small wire cleaning brush and the correct charger.
Before you start the charging process, you need to think about protecting yourself and preparing the space around you. Wear gloves and ensure that your work area is well lit and clear of other people, as well as potential hazards.
Next, identify which type of car battery you have so that you can work out which charger you need. If you have a conventional car battery, you can use a standard charger. However, if your car uses start/stop technology, then you’ll have an AGM or EFB battery and you will need to source a smart charger.
Top tip: If you aren’t sure on what type of car battery you have, you can visit your local car service and MOT centre for help and assistance.
A question that’s often posed to our technicians is “can I charge my car battery without disconnecting it?”. The answer is technically yes, but we don’t advise it. After a quick clean, we recommend disconnecting the negative lead first and reconnecting it last to avoid any shocks when touching the positive terminal. Once disconnected, move the leads to one side.
Top tip: Remember that if you disconnect your car battery, you may need to reset your radio and dashboard settings, so ensure that you have any PIN codes to hand.
If the terminals look dirty, use a wire brush and cloth to remove any corrosion or dirt. Cleaning away debris will prevent the charger from malfunctioning, which will help to extend your battery’s life.
If your charger comes with specific instructions, then make sure to follow those.
Situate the battery on a stable, flat surface ready to charge. Connect the battery charger’s cables to the terminals on the battery by matching positive to positive and negative to negative. Keep the charger as far away from the battery as the cables will allow, then plug the charger in.
Top tip: Start the charger on the lowest default rate to keep safe.
The battery manual will usually tell you how to spot when your battery is fully charged (or if it’s a smart charger, an indicator will tell you). Once the charger is ready to disconnect, unplug at the socket. Remove the positive cable first and then the negative cable, before reconnecting the battery to your car through the positive and then the negative terminal.
Top tip: Overcharging will damage the battery, so keep an eye on the charging process.
The length of charging time will depend on the type of car battery and battery charger you have. The time can vary between 10 to 24 hours. However, your battery or charger manual will usually inform you of the specific time, and some chargers even have a built-in timer. The best way to maintain a long life for your car battery is by recharging it slowly.
Car batteries can go flat for a multitude of reasons. It can be because of old age (five years is typically a good life cycle), if you’ve forgotten to turn your lights off after parking, or if you take frequent, short journeys and the battery doesn’t have enough time to recharge. A car battery is used to crank the car engine when it’s initially started, so it’s natural that over time it will lose its capability to hold charge.
If you’re wondering how to spot a weak car battery, the symptoms are usually noticeable. We’ve listed a few of the most obvious ones below:
· The car not holding charge for long
· A clicking noise when trying to start the car
· The engine backfiring
· A battery warning light blinking on the dashboard
· The engine taking longer than usual to ignite
· A loss of power to electrics
We hope our guide has taught you how to charge a car battery safely and efficiently. If you feel like you may need more hands-on help, then book in for a battery replacement or fitting. Or, to check on the overall health of your car, schedule a service or MOT.
