Using Battery Charger as Memory Saver (All You Need to Know)

Battery replacement these days isn’t as simple as they are back in the day. These new models rely on computers to operate everything. In short, you need to preserve the memory as you replace it. Otherwise, you may end up having all the settings reset. For this reason, you need a memory saver. Luckily, the battery charger can serve as your memory saver.

As you replace the battery, the car will lose its power. The process would reset all the settings in your car. If you have a battery charger, you can use it as your memory saver. This way, you can retain all the settings and memory while you replace your car battery.

In this article, we’ll cover all the things you need to know about battery chargers and memory savers. This way, you’ll understand how the concept works and how you can use it in your car.

Without further ado, let’s get into it!

Using Battery Charger as Memory Saver

What Is a Battery Memory Saver?

The first thing to understand is the thing we call a battery memory saver. While the name sounds obvious, you may still wonder what it is and how it works.

In general, a memory saver for your car battery is a connector with a small battery.

This battery has enough voltage and current to keep your car’s computer memory alive. However, since it’s only a small one, it will only be for as long as you change the main battery.

You can plug this connector into the car’s cigarette lighter or the OBDII connector.

In a nutshell, it works by keeping your car’s system alive while you replace the battery. This way, all the settings in your car will remain, and you won’t need to reconfigure everything again.

How Do I Replace Battery Without Losing Memory?

As I said in the beginning, replacing a car battery isn’t as simple as before. Back in the days, you simply unhook the battery and install a new one.

However, since newer cars these days run with computers and systems, you need to keep them alive. Otherwise, the settings in your car would reset.

As a result, it may mean the car would feel different when driven. Further, you may have to enter a security code to access the stereo.

Luckily, you can replace the battery while retaining memory.

Through this process, you can save yourself from resetting all the settings in your car.

Buy a small 9-volt memory saver.

This tool is available in almost any automotive supply store. Moreover, this tool is quite affordable, which means you don’t have to worry about expenditures.

Once you have it, you can plug it into a 12-volt accessory outlet or cigarette lighter on your car. This thing will provide a constant charge to the system while you take out the main battery.

Make sure the memory saver’s battery is new.

Once you know it’s fresh and new, you can plug it into the lighter. Moreover, you need to make sure the memory saver is working. 

You can know it through an indicator light, letting you know that the power reaches the device.

As you do so, you may have to turn the vehicle’s ignition to the ACC position for the tool to work.

Turn off all the other accessories on the vehicle.

Ensure all other accessories aren’t running—turn of all the lights, including the dome light and trunk light.

If your car has a light under the hood, you need to unscrew the bulb. In general, all accessories that need electricity will drain the battery saver, making sure everything is off.

Remove the battery.

Once you secured all the things above, you can then remove the car battery. Each model will vary, but most will need the plastic cover removed. The same thing applies to guards and mounting brackets.

As you work on the battery, remove the negative cables first, followed by the positive.

Install the new one quickly.

As soon as the battery is out, install the new one as quickly as you can. Reconnect the positive cable before attaching the negative. Make sure both cables got connected to the battery terminals.

Moreover, replace any guards, brackets, and covers you removed earlier. Once you’re done, turn the ignition and start the engine.

Once the engine is running, you can then unplug the memory saver from the outlet or the cigarette igniter.

battery charger

Do You Need a Memory Saver When Changing a Car Battery?

A memory saver is an entirely optional tool when you’re changing your car battery. However, in general, it does an excellent job of saving you from the hassle of resetting the settings of your car.

The primary reason you would want to use a memory saver is to save you some time reconfiguring your car’s settings.

Since changing the battery will lose power for a short time, all the settings will go back to their factory settings.

Of course, it’s a personal preference for every driver, and you can use it or not, depending on what you prefer.

In the end, it won’t harm your engine or your car whether you use a memory saver or not.

How to Make a Car Battery Memory Saver?

If you want to make your own car battery memory saver instead of purchasing one, you can do so through these steps:

Make an OBDII connector.

An OBDII connector is a tool that you may insert to your vehicle’s OBDII. While you can buy one online or at automotive stores, you can make your own at home.

An OBDII connector has 16 plugs, but you only need two pins to work with it. A piece of chipboard or wood can be used. After that, draw the hole in the correct location, just like the OBDII socket.

Place two nig head screws with a small back end that could go into fissures on the panel once it’s finished. On one end, the later part of the screw will go into the fissures and the screws, while on the other side, the heads will be in the cavities.

Make the diode and battery connector.

You must now operate on the power component after completing the OBDII hookup. To provide the required electricity to operate the program, link the cable to a battery.

Pin 16 must be connected to the positive side, and pin 4 must be connected to the negative side.

You’ll need a power adapter that’s compatible with the sort of cell you’re going to utilize. Your spare battery capacity connection will be the same as your replacement batteries.

The diode, on the other hand, is the most essential element. It will ensure that just one type of transport enters the vehicle.

Make proper insulation.

Handling the exposed metal wire sections of the stuff you produced is hazardous. As a result, you must tap the OBDII input screws.

The cables’ heads will not be revealed this manner; after that, wrap the diode and battery connected portion with the cable.

Test the memory saver.

The next step is to try it out before launching it. The meter will indicate zero flow of current when you attach the OBDII plug to your vehicle’s socket. It indicates that the diodes are operating properly to provide a one-way circulation.

On the other hand, calculating the energy above screw heads will display the strength of your cells on your multimeter’s display. It implies you’re ready to change your battery and recover your valuable computer with the storage manager.


Memory savers offer great help to everyone who wants to replace their car batteries without losing memory. This tool is relatively easy to use, and it’s also affordable. Another good thing is you can make your own if you don’t want to spend much.

Still, a memory saver is an optional tool, and you can replace your car battery with or without using it. It will all boil down to your preference or if you want to save some hassle from resetting your car’s settings.



Image credits – Canva

Share on:

My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more