How To Change A Car Battery Without Losing Settings? [2 Easy Methods]

Hi, I'm Luis Johnson, an automobile technician, and power equipment professional. By profession, I'm a businessman and operate a car workshop. I have created this...Read more

Changing a car battery is relatively easy. However, when we change the battery, usually, power is cut from the vehicle, and this resets the vehicle back to its factory dashboard settings, and the radio code also gets lost!

This typically means another trip to the dealership or garage because most people aren’t aware of their radio code! Also, nobody wants to lose their customized dashboard and car settings, do they?

Well, there are some easy ways to avoid this. You can either use a car memory saver or an external power source. But, to safely replace your car battery, you need much more information! So, below we shared some tips and tricks with a complete guide; you can follow how to change a car battery without losing settings.

Why Do I Lose Car Settings When I Change The Car Battery?

Well, if you’re looking to retain your settings, you should already know how to change a car battery in the first place. But, for those who don’t, let us briefly recap first. This will make it very easy to understand for everyone.

Short Recap On Changing A Car Battery

To change a car battery, you need to find the battery, disconnect the negative terminal first and then the positive terminal; then remove the battery from the tray, clean the battery tray, insert a new battery, and connect the positive terminal first, and the negative terminal at last.

But, there is a slight problem with these steps. If you follow this method, the vehicle is out of power for some time, which kicks off some anti-theft measures in many cars that resets the vehicle!

So, to stop this, we need to ensure that the vehicle is never out of power in the battery-changing process. That’s what we will discuss now, how to change a car battery without losing settings.

Changing A Car Battery Without Losing Radio Code or Settings

Changing a car battery without losing your dashboard settings means you’re not cutting off the vehicle’s entire electrical supply. To retain the radio codes or settings, a small electrical current must always flow through your vehicle.

Now, there are two common ways to do this. Either you can use a third-party car memory-saver device that should cost you around 50$ or do it yourself with a small, spare battery. Below we will discuss both methods.

Method 1: Using A Car Memory Saver Device

A car memory saver is a small device with a 12V battery that usually connects to your car’s OBD port. This device keeps the memory from your car’s computer from being erased. To use this-

Using A Car Memory Saver Device

Step 1: Buying a Car Memory Saver

First, you’ll need to have a car memory saver. Any memory saver from a good brand should work well.

Step 2: Secondary Power Source

The memory saver is essentially a secondary power source for your vehicle. So, you’ll need another 12V power source, such as a car or a jump-starting power pack.

Most memory savers connect to other power sources using a cigarette lighter mechanism. However, some have 12V battery connectors as well. So, depending on the type of memory saver you get, you need to know what type of power source you need.

Step 3: Connecting To The Vehicle

First, turn off your car. Then, depending on your memory saver, you should have an OBD-II port or a cigarette lighter that connects to your vehicle on the memory saver.

Connecting To The Vehicle

Connect the OBD-II cable to your vehicle. Now, connect the other end of the memory saver with the other source of power you have. You can use another car or a 12V power pack. Just make sure that the power output is steady at 12 volts.

Step 4: Replace The Car Battery

Now, replace the car battery as usual. After the battery replacement is complete, you must remove the memory saver from the OBD-II port and the power source.

This way, your car always has a small energy source, and the data on the car’s RAM won’t get erased.

Connecting a memory saver is the easy way out. However, there is another DIY solution for you if you don’t have a memory saver but have a spare 12V battery! Read below to find out more.

Method 2: Using A Spare 12V Battery

In this method, we will parallelly connect a spare 12V or 9V battery with the car battery already installed. This way, when we replace the other battery, the car will still have some source of electrical energy.

But, first, you will need some equipment.

Necessary Equipment

You’ll need-

  • A spare 12V battery
  • Two wires connected with alligator clips
  • Battery Connectors

Step 1: Connecting The Alligators

First, you’ll need to find your old battery and connect the red alligator clip to the connector/wire above your battery’s positive terminal and the black alligator clip to the wire/connector negative terminal.

Connecting The Alligators

Wiggle the clips slightly to ensure they don’t fall off with slight movement.

Step 2: Connecting The Battery

The alligators that we connected to the car’s battery on step-1 should have wires that either have alligator clips on the other end or some type of battery connectors.

The battery connectors should be color-coded. So, connect the red connector to the red or positive terminal and the black to the black or negative terminal. Do this very carefully because if you accidentally connect the red to black or vice versa this could create a short circuit in your car.

Step 3: Replace The Battery

Now, replace the battery as usual. But you need to be more careful not to slip off the alligator clips from the secondary battery and the car’s battery connectors.

After reconnecting a new battery in place of the older one, you can just disconnect the alligator clips from the secondary battery. To check if the process worked, you can check the time on your car’s dashboard.

If the time is reset, then the process fails. However, the process will work flawlessly if you do this carefully. Also, if you’re unsure how to replace the car battery, watch this video from “Scotty Kilmer.”

Frequently Asked Questions

Changing a car battery without losing settings should be quick and easy if you know how to do it. However, if you face any issues while doing this, you should check this section, where we answered some commonly asked questions about the method!

Do You Actually Need A Memory Saver To Change Your Car’s Battery?

Yes. Using a memory saver is the recommended way to go about this. However, you can use other types of secondary power sources, like a 12V battery. But, ensure you have secondary power to avoid losing important RAM information.

Will Disconnect The Car Battery Harm The Car’s Computer?

If you do not have any secondary power source, disconnecting the car’s battery entirely can make the ECU forget useful information that it collected over the years of use, which may cause driveability or starting issues.

But it shouldn’t harm the computer directly unless there’s a short circuit.

Why Does Removing The Battery Reset The Car’s Ecu?

Your car’s ECU stores its information on the RAM, which needs to be connected to some electrical power to ensure that the memory information is stored correctly.

If the car is disconnected entirely, this memory is flashed.

How Does A Car Memory Saver Work?

Car memory savers are simple devices that give your car just enough juice to keep it from flashing the RAM. It is essentially a small battery connected through the OBD II port or 12V socket. So, the car is never completely out of power, and the memory is saved.


As you’ve read this far in this article, replacing the battery without losing radio codes or dashboard settings should be easy. However, you should always wear gloves and other safety equipment when working on your vehicle.

Also, if you choose to follow the second method and use a spare battery, make sure that you connect the terminals very cautiously because if connected improperly, the car may have short circuits.

Have a good day, and keep working on your car!

Hi, I'm Luis Johnson, an automobile technician, and power equipment professional. By profession, I'm a businessman and operate a car workshop. I have created this site Batteryquery to help people purchase the right battery for their vehicles. The reason behind creating this site is to help my customers purchase the right car battery who often purchase the wrong one due to their lack of knowledge.

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