Charging a car battery can be a dangerous affair, but only if you don’t take all the necessary precautions or follow the instructions on your specific charger. The first rule in how to use a car battery charger is to always make sure that you have the right amperage for your vehicle. If you need help deciding which car battery charger to purchase, we’ve got a great guide for that. The next step is to read all of the instructions and make sure you understand them before you get started.
How to use a 12v car battery charger
A 12 volt car battery is designed to hold 48 amps when fully charged. They also generally charge at one amp per hour. You can use this equation to work out how long it will take your particular battery charger to give your car a full charge from flat.
Car battery chargers tend to start at 2 amps and go all the way up to 10 amps. The higher the amps of your car battery charger, the quicker it will get your car to a full charge. It’s essential to know how long it is going to take your charger to get your car battery to full capacity because overcharging your car battery can cause damage to it.
Things to remember when charging your car battery
Whenever you charge your car battery, remember to do it in a well-ventilated area. This is because fumes from the battery acid can be released as the liquid warms up during the charging process. It’s also important to loosen the vent caps on the battery so that those fumes can escape and they don’t build up inside the battery.
The instructions for many battery chargers will recommend that you remove the battery from your car before starting. This is to protect against any surges in power that could damage automated functions in your car. It will also stop you from accidentally trying to start your vehicle while the charger is attached.
When taking your car battery out, make sure you disconnect the grounded terminal first. It’s also important to ensure that everything in your car is turned off – all the added-on accessories too. This will prevent any sparks that could cause a fire or your battery to explode.
You may also need to give your battery a clean before you charge it, if you haven’t done so in a while. Be very careful when you remove any corrosion on the plates and terminals. While you are busy, do not touch your face as you may transfer battery acid to your nose, mouth or eyes.
How to connect a car battery charger
The first step is to read the instructions. Once you feel comfortable that you understand how the charger works and what you will need to do, it’s time to double-check your car’s manual. Read up about the battery and the electrical systems used in your vehicle.
Next step, ensure you have somewhere safe to put the charger for the duration of the process. Never place the charger on top of the battery it is charging or vice versa. It’s best if you can place the charger as far away from the battery as the cables will allow. Finally, when you’re ready, connect the charger to your battery and begin charging.
Your battery will have two terminals – positive and negative. Generally, the positive terminal is larger than the negative, making it easy to distinguish between the two. It’s also important to note that one of these terminals will be the grounded terminal, meaning it is connected to the vehicle’s chassis. If the battery is still inside and connected to your car, always start by connecting the correlating clip to the ungrounded terminal. Then the other clip should connect to the chassis or the engine block.
If you have taken your battery out of your car, it’s a simple case of connecting negative to negative and positive to positive. Just be sure to connect the clips to the terminals first and then to the charger to complete the circuit.
Types of car battery chargers
Aside from the basic plug and play options, you get some fancier chargers:
- Trickle chargers – These are designed to maintain a specific level of charge over a long period of time. They’re perfect for vehicles that you don’t use that often, like your weekend roadster or your campervan that takes you on holiday every summer.
- Smart chargers – A smart charger will work as a combination of a standard charger and a trickle charger. They tend to give a strong charge until your battery reaches around 80%. The mechanism then switches over to a trickle function to slowly increase the charge level to full capacity. They are then designed to switch off the charging function but continue to monitor the level of your battery. If the charge falls below a certain percentage, the trickle function will kick back in to get you back up to 100%.
Why would you need a car battery charger?
Every time you start your car, a big portion of the charge from your battery is used. The design of a car is such that the battery is then recharged while you drive. However, you don’t always recharge your battery fully each time you drive – especially if you only take short trips on a regular basis. This can cause your battery to get drained and require a quick pick-me-up from a charger.
Other drains on your battery include the use of the air conditioning or the heater, the headlights, windscreen wipers and other electronic systems within your vehicle. Using your car to charge your phone while you drive can also cause a drain on the battery that doesn’t get recharged on a short trip.
Having a car battery charger around can save you a lot of trouble because you’ll be able to get yourself back on the road in no time. You can also look after your battery if either you only drive it down the road and back on a regular basis, or your car is left standing for long periods of time.