How to Replace a Car Battery and Keep the Computer's Memory

This is a video tutorial on how to change out a 12 Volt battery on any modern automobile including Tesla and other electrics. This applies to pretty much every car made after 2014 or so. With today's modern computer controlled cars there is a special way to change a battery. A once easy repair now made just a little harder. But I am showing you exactly how to replace that battery and save you all kinds of money!

Also DO NOT start the vehicle with just the jump pack attached.

*Disclaimer: Please use all safety precautions

[davidv]

Replaced the battery in a 2019 Mazda 3. I hooked up a small one amp Century charger which provides approximately 13.5 V to the negative and positive terminal lines before disconnecting the battery. Had battery out for about 10 minutes while I cleaned the posts and took my time. Zero problems and worked like a charm. No settings lost. I returned the Memory Saver unused as I read they are quirky after buying it.

[JPKuztoms]

Well, I ended up hooking up normal jumping cables to a running car, then switched the battery keeping the terminals still connected, it worked like perfect

[jgomez]

Thanks for the info, DIYers appreciate people like yourself

[southernlonghorn]

Thanks buddy, had some wonky strange error codes on wife’s 2019 Tiguan and slow starts. Did some digging and learned that changing the battery could cause lots of other memory, key, code, various issues. Did your trick and it worked GREAT and various low voltage codes went away. Keeping the alligator clips on the terminal cables was difficult.

[jeffbrassard]

Nice video work, good “how too” instruction covering all the key points.

[jfmartel]

By far the best video on how to change a car battery with an external power source.

[alessandrotemistoclesalvat]

Good morning sir, sorry for my English (I’m from Italy).
Images are very clear during all the video.
Your English is very clear: I could understand everything even though my comprehension level is medium.
Each part is easily visible.
I’m not very confident with car fixing, but this video seems to be very clear.
So I will buy a power supplier before change the battery and next time I will try to follow your instructions instead of taking my car to a garage.
Thank you.

[anthonyvilla]

Awesome video you're saving me over 100 dollars brother 🤙

[troypierce]

Really great instructions you gave. I thought they where pretty through ! Thanks very much !

[jadney]

On most cars, the cig lighter socket is dead when the key is off, so powering there won't help, and you don't want to turn the key ON, because that will draw more current than the low current mode can supply. OTOH, it was nice to see that M-B provided a nice + terminal for this exact purpose.

[beethns]

A couple of things. It's a huge issue with the 2007 Lexus LS460. If you change the battery in a 2007 Lexus LS460 without using a Memory Saver/Battery Saver you will likely end up getting the following message on your navigation screen. A program cannot be read. Please consult to a dealer. When this happen you have no option but to engage the dealer. Also, if you use the cigarette lighter option you risk loosing power to your car's computer if the cigarette lighter outlet has a timeout feature. I would strongly discourage using this option unless you are ABSOLUTELY sure your vehicle's 12 volt cigarette outlet does NOT timeout.

[moondog]

Hello. As one other person has asked: What is the connection at the other end of the spliced-in alligator clips and where does it connect to on the jump pack?

[kunder]

Awesome videos for modern cars. bring back (1931 ford model A ) something i can work on.

[stevemurnane]

If using the cigarette lighter socket, be sure to turn key to accessory or to the on position, as most are not powered with the key off. Electrons can't get out if not switched.

[psdaengr]

In Japanese carsand may others, the 12 volt convenience outlet may be controlled by a relay that is energized by the 12V battery which means that to be safe you should connect the keep-alive replacement directly to the battery cable terminals,

[peterduxbury]

I didn't have the Radio Code for my Toyota, and (by removing the Car battery) you would lose this! At the time, I didn't figure on the Cars' ECU and potential Memory Loss. But here is how I replaced the Car Battery - without any losses to the radio or ECU. The Cigar Lighter Socket was permanently 'live' with the Ignition turned-off. So I set-up a 12V (regulated) 1-Amp DC Supply which was fed from the mains by an Extension Cord. I wired a Cigar Lighter Plug to the 12V / 1A DC regulated supply - remembering the correct polarity. I then plugged this into the Cigar Lighter Socket, and proceeded to change the useless Car Battery, and replace this with new. I had never seen any videos, or even knew how to do this. But everything worked out just fine. With the new Car Battery Connected, I just simply removed the Cigar Lighter Plug from the Socket. Hope that this helps others.

[felixalbion]

Been doing something similar with jump leads for years mostly to save the stereo if I did not have the codes for it.

[DAK]

My jump pack came with an OBDIi connector. That works even if the lighter port is switched. I also noticed that you didn't clean the battery cables before attaching the new battery. Always clean the cable ends and the battery posts before you connect them. Modern cars are very voltage sensitive and you want a good, clean connection. You can get a wire brush terminal cleaner for less than $5 that makes the job easy.

[dwtubeyou]

Terrific video and thanks! To confirm: To replace the battery, one has to follow use THIS video's procedure, to preserve the ECM, and then step 2: Reset the Battery Mgmt System using your other video. Right or is there a 3rd or 4th step which I'm omitting? Will the other video be applicable to a Kia Seltos?
If one doesn't want to spring $100 for a jump box, what would a typical mechanic charge (labor) to replace an AGM battery brought to him (or her?) by the customer?

[trainmaster]

I kept my computers memory by using a solar battery charger placed on the dash board. Disconnecting the battery and leaving the charger plugged into he cig lighter kept the computer with enough power so it didn't lose it's memory during the battery removal.