When a car refuses to start, it may be an indicator of an issue with the car battery. If this is the case, you'll need to recharge it. Fortunately, this is typically a straightforward process. Follow these steps to ensure you do it correctly.

How to Charge a Car Battery 

1. Turn Off All Car Electronics 

To keep yourself safe, shut off all the vehicle's electronics and handle the battery with care. Switching off electronic features, such as the interior cabin lights, ensures an arc discharge doesn’t happen while the battery charges. 

car battery

Another safety hazard to look out for is battery acid. This acid is toxic, so contact with clothing and skin can cause chemical burns and sickness. Watch out for leaks before handling the battery to avoid these problems.

2. Clean the Terminals  

If the terminals have dried sulfuric acid—a toxic white powder—it is unsafe to touch them. Sandpaper pads, terminal cleaning brushes, battery cleaning solutions, or a wet cloth with baking soda can effectively clean the terminals. This step keeps out dirt, neutralizes battery acid, and lessens the chances of malfunctions while the battery recharges. 

3. Remove the Cell Caps 

Some batteries do not have cell caps, but if yours does, remove them so that the gases formed during charging can safely exit. These small caps are found on the top of the battery or under a yellow strip.

4. Set Up the Trickle Charger

Make sure the charger is off for you and your vehicle’s safety. Connect the cables to the terminals by connecting the red wire with the positive terminal first and then the black wire with the negative terminal. Typically, the terminals are marked “NEG” and “POS” on the battery. Keep the clamps apart, or they may spark and cause a fire. 

Plug the charger into an electrical outlet and turn it on, beginning with the lowest rate. Your car's manual should provide instructions on how long to charge your battery. When the charging is complete, turn the charger off before disconnecting the cords.

5. Check the Battery 

A hydrometer shows the amount of energy in the fluid. Turning on your vehicle also allows you to see if the battery is fully operating. After these steps, if your battery does not charge, it likely means you either need a replacement or there is an underlying problem with your car. In this case, a professional will need to examine the battery and vehicle.


If you're having trouble charging your car battery or need a new one, contact M & C Tire. This family-owned and -operated company serves drivers throughout Kalispell, White Fish, Columbia Falls, Big Fork, Lakeside, and Somers, MT. They carry a wide range of Interstate® batteries and will start or replace yours quickly to get your vehicle running again. Call (406) 752-9662 to schedule an appointment, or visit them online to learn more about their services.