How to change the battery on modern cars?
The cars of later models have many computerized systems, in most cases each system is under the basic control of its computer (module). Each car can have more than twenty modules, and many of these modules have some kind of own memory that can be lost when the battery is disconnected. This can lead to something of a minor nature, such as a time malfunction on the watch or the position of the seat or steering wheel, but it can also cause the engine to stop or even malfunction in the system.
To avoid this problem, you need to know that the power will not be supplied to the electrical system when the battery is disconnected for any reason, including replacement. Fortunately, there are many available "memory devices" that can be connected to the cigarette lighter or the OBDII diagnostic connector. These devices will provide sufficient power for the modules when the battery is disconnected so that they do not lose memory.
Be sure to follow all the manufacturer's instructions if you use any of these devices with memory retention. Most of these devices use a small battery for power.