When replacing a car battery, most people disconnect the battery completely before installing the new one. This causes your cars’ computer to lose its stored data. Seat position, navigation system, radio presets and much more settings might have to be reset. And if Murphy has its way, other electrical car accessories will stop working too and will need to be reset with an OBD scanner.
However, this doesn’t have to happen, because there are 2 easy ways to save your cars’ memory and settings, and prevent all these issues: you can either use an OBD2 memory saver, or an external power supply.
In this “How To”, we’ll guide you through the process of replacing your car battery without losing your computer settings and other presets.
If you prefer watching a video instead, we’ve also got you covered! Check out our YouTube video:
Right, let’s get crackin’:
Here’s how to change a car battery without losing your settings using an OBD2 memory saver:
Step 1: Plug in the OBD2 memory saver
First plug the OBD2 memory saver into the OBD2 port at one end and hook up any 12 volt battery at the other end.
Some OBD 2 memory savers also come with a battery tray that you can fill with 8 1.5 volt batteries (=12V) in case you don’t have a spare 12 volt battery.
Step 2: Disconnect the negative battery cable
With the battery saver connected, you can now replace your battery without losing any settings. You want to disconnect the negative battery cable first, before disconnecting the positive one. With the negative cable disconnected, you can’t accidentally create a short when the positive cable touches a random metal car part. This way, you won’t have sparks flying everywhere, and avoid potential injuries.
Step 3: Replace the battery
When installing the new battery, you want to hook up the positive terminal first, and the negative terminal last, again to avoid accidental shorts. Finally, disconnect the battery saver and you’re ready to go.
Here’s how to change a car battery without losing your settings using an external power supply. (our preferred method)
Step 1: Hook up a 12 volt power supply directly to your battery cables
Connect the 12V power supply directly to your battery cables. It’s completely safe: it’s spark- and reverse polarity protected. Depending on your device, you might have to select “supply mode”. The great thing about this method is that the electricity follows the regular route, just like with the car battery connected: through the fuse box which protects all the sensitive electrical components.
Step 2: Disconnect the battery cables
Next, disconnect the battery cables and move them to the side, making sure they stay connected to the power supply at all times and see to it that they don’t touch each other or any metal parts.
Step 3: Remove the old battery
Remove the old battery and put the new one in, but be careful you don’t accidentally disconnect the power supply from the battery cables.
Step 4: Tighten the battery cables
Before disconnecting the power supply, you want to first tighten the battery cables to avoid power interruptions.
After the battery terminals are properly secured, you can disconnect the power supply and reinstall the battery retaining bracket, if your car has one. Be careful not to touch the positive battery terminal with the bracket or your wrench, because this will create a short, and early 4th of July fireworks.
Once the battery is firmly in place, you’re done.
That’s all there is to it!
Happy cruisin’!
