How to Change Your Car Battery

Knowing how to change a car battery is vital. Modern automobile batteries work harder than ever. They power an expanding range of electric components, some of which continue to draw electricity even when the vehicle is off — a phenomenon known as parasitic drain. Phantom loads can help diminish your battery’s capacity, accelerate wear and increase the chances of failure, especially when it loses more charge than it gains.

Although mastering proper diagnostics can save money by not spending on premature replacement, learning how to remove a car battery is crucial. Your current one may quit on you without warning, and help may take forever. You must feel confident and comfortable getting your hands dirty. It fosters self-reliance and will protect you from the risks of being stranded in the middle of nowhere at the worst possible time.

How to Change a Car Battery

Although car battery replacement sounds intimidating, it’s straightforward. Follow these steps to remove the old one and install the replacement correctly, efficiently and safely.

1. Collect Your Tools

Ensure you have these essentials before you begin:

• Safety goggles and gloves
• A socket wrench — ideally the one suitable for various socket sizes
• A baking soda-water cleaning solution
• Steel wool or a wire brush
• Cleaning towels
• Anti-corrosion washers
• Corrosion-resistant gel

A battery terminal puller is optional and helpful when you struggle to lift the battery.

You may need a couple of extra tools if you’ve got a weird model, like a Dodge Stratus. In this car, manufacturers hid the battery behind the bumper on the driver’s side. To access it, you must jack up the car, remove the driver-side wheel and remove the fender skirt. From there, you can unbolt the battery and cables.

2. Buy a Replacement

Now, it’s time to buy a replacement battery. You can find one at a parts store, dealership or a local big box store. In addition to the price of the battery, the store may charge you a core fee. You can reimburse it when you bring your dead unit for recycling.

3. Locate the Battery and Terminals

Modern car batteries typically are under the hood. If you can’t find the battery, review your owner’s manual. The chances are that it’s hiding in the trunk. Ensure the engine is cool. Otherwise, it’s going to be too hot to the touch.

If you don’t know where your car battery is, review your owner’s manual. Chances are, it’s in the trunk. Like the above Dodge Stratus example, accessing it may require more elbow grease.

Once you locate the battery, you must identify the terminals. The positive one has a red cover marked by the plus sign, whereas the negative has a black cover marked by the minus sign.

4. Detach the Terminals

Now that you have a new battery, it’s time to get your hands dirty. First things first — wear personal protective equipment to keep your eyes and hands safe from harmful substances.

Once your gear is on, loosen the nut from the bolt that connects the negative terminal cable to the battery. Some batteries also have quick-release clamps, which don’t require tools to remove.

Once loose, place your tools on the ground or in a Styrofoam tray to prevent a spark. Then, slide the end clamp from the terminal. Repeat the process when removing the positive cable next.

5. Take Out the Old Battery

Now that both terminals are loose, you can unfasten the plate that holds your battery in place. You’ll likely see the same-sized nuts as the ones on the cable clamps. You might also find a wing nut you can unscrew with your hands. Once free, it’s time to remove the battery. Remember, batteries are heavy. Lift with your knees to prevent injuring your back.

Most batteries have an attached handle for easy carrying. Lift straight, then place it next to your feet on the ground. Grab your battery terminal puller when necessary. If the part looks corroded, be careful of acid spilling out as it moves.

6. Clean and Dry the Terminals

Corrosion spells disaster not only for radiators — it’s also bad news for terminal connectors and battery trays. Take this opportunity to rid goo off the terminals.

Mix baking soda with water to make a safe potent cleaner from scratch. Apply it to the problem areas and use your steel wool or wire brush to remove all the gunk. Wipe them clean. Allow the damp spots to dry before proceeding to the next step.

7. Insert the New Battery

Prepare the replacement unit. Remove the red and black plastic covers from the battery posts and place the anti-corrosion washers. Coat the terminals with corrosion-resistant gel.

Put the fresh battery into the tray. Ensure its positive and negative ends match their corresponding terminals. Clamp the battery to secure it. When it doesn’t budge, you did a stellar job.

8. Reattach the Terminals

When installing a car battery, the positive terminal should go first. Connect it to the positive battery post, tighten the connection with your wrench and repeat the process with the negative terminal.

Mistakes When Changing a Car Battery

You don’t need to be a brain surgeon to learn how to change a car battery. After all, the steps are simple and easy. Still, you can commit mistakes, regardless of how often you’ve done it.

Blundering the replacement can have adverse consequences. Avoid these common mishaps if you want to do it yourself correctly.

1. Buying an Incorrect Replacement

Automotive batteries come in various sizes. If you have an untrained eye, getting an incompatible unit is too easy.

Use all the resources available to make the right choice. Consult your owner’s manual to know your current battery’s exact specifications. Use the store’s fit guide to aid your decision-making.

When in doubt, seek expert advice from a mechanic, a representative from your battery manufacturer or a roadside assistance professional.

2. Neglecting the Warranty

A car battery can be a significant expense. Compare warranties as you would replacements to avert any additional expense if the new one is faulty. Spending an extra $100 on a four-year warranty is worth it.

3. Overlooking Safety

Changing lead-acid batteries accident-free multiple times can lull you into a false sense of security. However, they contain hazardous substances, so wearing no protection can expose you to them and jeopardize your health.

4. Misidentifying Terminals

Mistaking a positive battery terminal for a negative one, and vice versa, can fry the car’s electric components at best and cause an explosion at worst.

5. Rushing the Process

Car battery replacement is a delicate process. Doing it in a hurry increases your chances of committing a mistake. Be patient and exhibit attention to detail.

6. Skipping Post-Installation Checks

Before you hit the road, double-check the connections’ correctness, measure the voltage and determine whether the electric components work. These safety precautions allow you to spot and address issues early.

7. Forgetting About Battery Registration

If you own a German car, it may have a Battery Management System. If so, you must register the replacement. Doing so enables your car to adapt to a fresh battery after adjusting to the old one, ensuring everything works efficiently. Otherwise, your vehicle may shut down its electrical system or not start.

How to Perform a Battery Performance Check

Treat replacement as a last resort. Classic auto battery issues include failing to start your vehicle, struggling to power electric accessories and experiencing start-stop tech problems. However, none of these automatically mean your unit is beyond saving. More often than not, you only need to recharge it.

Many car owners don’t think about charging batteries because they seldom have to. The built-in charging system generally handles this job. The alternator helps power electric components and charges the battery while the car is in motion, keeping the voltage within the optimal range. The problem is your vehicle can’t recharge effectively when you spend little time on the road. Short or infrequent commutes cause the battery to discharge more power than it receives.

To perform a battery performance check, you can do tests to measure its voltage at rest or while the vehicle is on. The latter requires a helper, but either can give you an idea of whether to recharge or replace your car battery and eat the cost.

Various devices can measure automotive battery voltage. The ammeter, voltmeter and power probe are staples of a mechanic’s arsenal of tools. Still, the multimeter is your best bet for doing a battery performance check at home.

A multimeter can measure numerous electrical properties, including voltage. It’s versatile and as intuitive as one-trick ponies, so it’s worth the expense if you want to know the ins and outs of changing a car battery.

Multimeter designs vary by model, but the most critical label for automotive battery performance checkups is the straight line above small dashes, symbolizing direct current (DC). You may also see millivoltage (mV) and voltage (V) values, typically 200mV to 600V. Advanced units have auto-ranging functionality, which can detect the ideal voltage range you want to measure to save time.

How to Measure the Resting Car Battery Voltage

Using a digital multimeter without auto-ranging, follow these easy steps to check battery performance:

1. Switch off the ignition and all accessories.
2. Pop the hood and locate the battery.
3. Ensure the terminals are clean and corrosion-free.
4. Set the multimeter dial to 20V to measure between 0V and 20V.
5. Attach the red probe — also known as leads — to the battery’s positive terminal.
6. Put the black probe onto the battery’s negative terminal.
7. Check the reading on the display. Fully charged batteries should have a 12.2V-12.6V resting voltage. A negative voltage reading means you mismatched the probes with the terminals, although the number is accurate.

A slight dip below the range’s lower end means you must charge the battery overnight until full. If it can hold a 12.6V charge while disconnected from the car, it’s perfectly fine and something in the vehicle is sapping its juice faster than the digital clock and computer memory.

A severe decrease indicates deteriorating battery performance. Unlike a faulty car air conditioner that makes strange noises when it needs recharging, a dying battery quietly demonstrates underperformance. If you need to jump-start your battery frequently, it’s a tell-tale sign that it’s on its last legs.

Regardless of the result, you may have to retire your lead-acid battery battery when it reaches a certain age. The older it gets, the faster its rate of deterioration accelerates. Find out its manufacturer’s estimated service life to know how many years you can reasonably rely on it.

How to Measure the Car Battery Voltage During Cranking

Determining the voltage level your battery can hold during the crank cycle gives you an idea of how much electricity it can handle when various components draw power from it.

With a helper, follow these steps to conduct this manual battery performance check with a digital multimeter.

1. Turn your car off and all accessories.
2. Open the hood and find the battery.
3. Ensure the terminals have no dirt or rust.
4. Dial the multimeter knob to 20V.
5. Place the red and black leads to the positive and negative terminals, respectively.
6. Ask the helper to turn on the ignition for 15 seconds max.
7. See how the readings change on the multimeter. The voltage reading should change from the resting level, which should drop initially before rising once the vehicle starts.

A vehicle with a healthy battery keeps a charge of 12V after triggering the ignition. Once it starts, it should maintain a voltage of 14.4V-14.6V. Any reading below either threshold suggests the battery is weak and unreliable.

You can use a home charge to replenish its juice or take it to the shop for further investigation. A drained battery may just be a symptom, not the disease.

Your car has tens of thousands of components. Only one must malfunction to keep your vehicle from starting or cause electric features to act up. For example, you may encounter engine misfires when you have a faulty spark plug, even though your battery is in good shape. You may also see the battery warning light come alive when the alternator or the electrical system is shot.

When another part is broken, changing a car battery does nothing without identifying and addressing the true culprit. The only way to get to the bottom of the snag is to check your vehicle thoroughly.

When to Call for Help

It’s easy to replace a battery when you’re at home in the garage. Yet it’s tough when you get stranded on the side of the road. Call for help if you can’t start your car, or you don’t have the necessary tools.

It’s smart to invest in a roadside assistance program that has your back in times of need. These organizations offer a range of services, from a jump to get home to a battery replacement.

Change Your Car Battery — A Simple Guide

If you have what you need, changing your car’s battery is easy a pie. Simply follow the steps above, starting with collecting the right tools. If you get stranded on the side of the road, be sure to call for help.