When the engine is running, the main source of current – the generator – supplies electric current to all consumers, including the ignition system, and charges the battery.
If the red low battery indicator light is on in the instrument cluster, it means that the current is not flowing from the generator to the on-board network and the battery's energy reserve is being used up. It is unacceptable to operate the car with the low battery indicator light on, since sometimes the cause of the light may be a short circuit in the wiring, leading to a fire in the engine compartment of the car. Stop the car, turn off the engine and determine what malfunction caused the light to come on. If the cause of the malfunction was not a short circuit, and the battery was fully charged, you can drive to the garage without the generator, but it is better to try to fix the malfunction on the spot.