If the alternator or voltage regulator does not work, you can continue driving, as the battery is temporarily sufficient for this.
Gasoline engine: during the day the battery current will last for some time, although the ignition system needs a minimum voltage for normal operation and fuel injected engines with various sensors, injectors and fuel pump depend on the battery current. Depending on the capacity of the battery, it can last for approximately 5 hours of driving.
Diesel: since a diesel engine does not need to be ignited and can be operated with a faulty generator if it is started without electric current, the duration of the trip on it is theoretically unlimited. However, since the shut-off valve is powered by electricity, it consumes battery power.
Current consumers such as lighting, flashing signal device, windscreen wiper, etc., reduce the possible travel time with both types of engine. Therefore, save energy - this is the main rule.
1. It is not necessary to interrupt your trip. The starter and preheater require a lot of electricity. If possible, let the car coast.
2. The rear window heating, fan and radio must be turned off.
3. Use the windshield wiper and washer as little as possible.
4. Drive at night without high beam headlights and fog lights.
5. Disconnect the alternator multi-pin connector to avoid draining the battery due to a faulty alternator or voltage regulator.
6. In order to absolutely exclude damage to the generator during the continuation of the trip, it is necessary to remove the voltage regulator.