How to change a Car battery Safely - Which wire to disconnect first? Plus don't lose memory settings

Summary

This video guides viewers through the process of safely replacing a car battery, highlighting key safety precautions to avoid shocks, fires, or battery explosions. It explains how to identify whether your car is negatively or positively grounded, the correct order to remove the battery terminals, and essential tips for handling the battery and avoiding injury. The video also covers additional steps like cleaning the battery tray, applying dielectric grease, and reinstalling the new battery. Bonus tips include recycling the old battery for a refund and ensuring all vehicle settings are preserved during the replacement.

Takeaways

• 😀 Always remove the **negative** terminal of the battery first to avoid short circuits and injury.
• 😀 Most cars are **negatively grounded**, meaning the negative terminal is connected to the car body.
• 😀 Before starting, check your car’s owner’s manual to locate the battery, as it may be in the trunk instead of under the hood.
• 😀 If concerned about losing settings, use an OBD memory saver to preserve radio presets and other settings when disconnecting the battery.
• 😀 If your vehicle stereo requires a security code, be sure to have it ready before disconnecting the power.
• 😀 The correct size socket (typically 10mm) is essential to safely remove the battery terminals.
• 😀 When removing the battery, always keep it upright to avoid spilling battery acid, which could cause damage or injury.
• 😀 Clean the battery tray and area before installing the new battery to ensure proper fit and function.
• 😀 Apply **dielectric grease** on the battery terminals to prevent corrosion and ensure long-term battery performance.
• 😀 Always reconnect the battery cables in reverse order: **positive** first, **negative** last, to avoid electrical issues.
• 😀 Return your old battery for recycling to avoid the environmental fee and ensure safe disposal of hazardous materials.

Q & A

Why is it important to remove the correct battery terminal first?

Removing the correct terminal first ensures safety by preventing short circuits. For most cars with a negative ground system, you should remove the negative terminal first to avoid creating a spark or causing a potential explosion when working with the battery.

What could happen if you remove the positive terminal before the negative terminal?

Removing the positive terminal first can cause a short circuit if you accidentally touch any metal parts of the car, which could result in a spark, fire, or even an explosion due to the direct connection of the negative terminal to the car's body.

How do you determine if your car is negatively grounded or positively grounded?

Most cars are negatively grounded, meaning the negative terminal is connected directly to the car’s body. You can check your car's manual if you're unsure, but the majority of vehicles use a negative ground system.

What is the purpose of using an OBD vehicle memory saver when replacing a car battery?

An OBD vehicle memory saver helps preserve settings like radio presets and vehicle preferences, preventing them from being lost when the old battery is disconnected. It can also help prevent rough idling as the car relearns its air/fuel ratios.

Why should you avoid tilting the battery while removing it?

Tilting the battery could cause acid to leak out, which is hazardous. Keeping the battery upright ensures that no acid spills, which could damage the car or harm you.

What safety precautions should be taken when cleaning the battery posts?

Wear protective eyewear and a mask to avoid inhaling metal and corrosive particles when cleaning the battery posts. Be careful not to let the particles get into your eyes or lungs.

What is the purpose of applying dielectric grease to the battery terminals?

Dielectric grease is applied to prevent corrosion on the battery terminals. It helps protect the metal from environmental damage, ensuring a stable electrical connection.

What is the correct order for reinstalling the battery cables?

The correct order is to install the positive cable first, followed by the negative cable. This order helps prevent accidents, as connecting the negative terminal last reduces the chance of a short circuit.

What should you do if your car's stereo system requires a security code after replacing the battery?

If your car's stereo system requires a security code, make sure you have it before disconnecting the battery. This code is typically found in your car’s manual or on a card provided by the manufacturer.

What should you do with the old battery after replacing it?

You should return the old battery for recycling. Many places offer an environmental fee for the new battery, which can be refunded when you bring the old one back. Always keep your receipt to claim the refund.