Replace Car Battery Without Losing Data

What is the best way to replace a car battery without risking losing settings, such as those of the radio?

"For example, I'm familiar with the CTEK MXS 7 or 10, which offer such a function, but I'm looking for a more affordable solution. Dealing with three batteries is also not an option."

Hello,

I've always done that with a second vehicle so far.
Simply connect it to the jump start terminals in the engine compartment and replace the car battery.

WARNING! The exposed positive terminal on the vehicle side is live and carries electricity; protect against short circuits. I always wear a mechanic's glove over it, and nothing can happen.

If the vehicle has a Battery Management System (BMS), please remember to enter the new battery type – if different – and the "new" serial number into the coding. Changing just one digit of the previous serial number is sufficient.
The new battery should be fully charged before installation; so far, none of the ones I've bought have been completely full, only about 80%.

The state during recoding is important for the BEM reference, so please load it completely.


Regards, Mpire.

Mpire wrote:

Simply connect it to the jump start terminals in the engine compartment and replace the car battery.

However, these are not installed in every vehicle. If none are present, you need to connect to the positive terminal.

Hi!
I have a small device for that; it contains a battery, similar to a small motorcycle battery.
It will then be connected to the OBD socket with a cable.

I don't have vehicles that are quite so state-of-the-art and technologically advanced.
So far, this has worked well with my relatively simple cars.

Steffen G wrote:

I don't have vehicles that are quite so state-of-the-art and technologically advanced. So far, this has worked well with my rather simple cars.

It's not about super modern cars, but rather my wife's 1997 Polo in this case. Specifically, the problem is with the Alpine radio, which immediately loses all its settings. And it's no fun trying to restore the DAB station list.

This car has a constant power supply at the cigarette lighter socket – if it even has one. Basic models of that era often had this feature omitted. What would normally be an annoyance, such as for forgotten heated seat cushions, is actually quite advantageous in this case. The cigarette lighter provides enough power to maintain the memory (the outer part is negative, and the contact in the middle is positive). A power supply with approximately 12 volts is sufficient. I used one that was previously used to power (CB) radios. If you leave the ignition off and also turn off the interior light, a small AC adapter with approximately 12 volts should be enough.

The warning about the positive terminal on the battery still being under voltage has already been mentioned. With the suggested gloves, it should work; a Velcro strap can be used to secure them for extra safety. For this car, nothing needs to be reset. If the replacement is done without interruption, the car won't even notice the new battery.

Hutfahrer wrote:

This car has power permanently available at the cigarette lighter socket, if it even has one.

He has.

Hutfahrer wrote:

If it's done without interruption, the car won't notice anything about the new battery at all.

That's clear.

I think the solution of supplying power to new vehicles via the OBD port is very good, because they will definitely detect that the voltage was interrupted there.