If a gas powered car’s alternator goes out you have seconds to move over to the side of the road before the car dies. I know as it happened to me. At least a alternator is cheap to replace.
If a failed alternator shut down your engine instantly, you had bigger troubles than an alternator. Your battery has over an hour of run time. That you didn’t notice the charging system’s idiot light isn’t the alternator’s fault.
A car should run quite a ways without the alternator as long as you don’t use the lights, radio, horn, etc.
Only with an already weak battery. I once managed to limp home when this happened, at night in the winter, by turning off anything that sucked power. When the car started stuttering I turned off the heater (motor) - car picked up again. I turned off the radio and even the main headlights for half a mile...I literally rolled into my parking spot.
Any car will continue to run just fine after the alternator fails until the battery dies. That would take at least an hour.
Depends on how it ‘goes out’; as the BATTERY is still hooked up and supplying power to EVERYTHING.
I lost a serpentine belt in the winter and drove 20 miles down the interstate to the next exit.
HOW? one might ask; for the belt turns the fan/water pump.
There was enough air coming thru grill at highway speed to spin fan and turn the pump.
Plus, it was VERY cold outside so not that much heat was being dumped out thru the radiator.
Also; it was daytime and power hungry headlights were not being used. Also; all unneeded accessories were turned off, including the heater fan.