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

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.

Thanks for the info, DIYers appreciate people like yourself

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.

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

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

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

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.

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

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.

Loved the video, Many thanks.

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

Excellent video. Thank you,

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

Thanks for the helpful tips.

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?

Thank you for the info

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,

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.

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.

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