We can easily measure the voltage (and therefore the charge level) of our car battery in simple ways:

• The simplest case, of course, is to have an indication on the dial or even hidden in one of the car's menus. While this is almost the norm in trucks and heavy commercial vehicles, it is relatively rare in passenger cars.
• There is always the possibility of having an indication from the car's electronics, by connecting an adapter to the OBD port. Such components come in a wide variety of costs, connection methods and capabilities and provide us with real-time measurements of almost all vehicle parameters.
• Usually some battery manufacturers put a transparent circular plastic "eye" from where we can see green or red depending on the level of charge, seeing at a glance whether the voltage is good or not respectively.
• he best combination of simplicity and reliability is the multimeter solution. Even a very cheap one will directly measure the voltage of both the battery and the dynamo (if the engine is running).
• Finally, the more specialized instruments used by vehicle electricians give reliable information about the internal resistance, and thus the health of the battery.

Don't forget that prevention is irreplaceable and a few minutes of our time for a free battery and charging system check can prevent several unpleasant surprises!