If you suspect that your car’s alternator is not working but still need to drive then there are a few important things to keep in mind to be able to get as far as you can or drive for as long as you can safely.
This post provides answers to these 5 questions you may have should you find yourself in this situation.
1. Can a Car Run without an Alternator?
Yes, a car engine can run without an alternator even though the alternator is the primary source of power provided the battery has sufficient power to run the car’s electrical system.
The alternator may not be functional, or not be connected, or there’s no alternator belt. As long as the car battery still has sufficient power to start the car and power the car’s electrical system then you can drive the car!
However, once the battery runs out of power, the car engine will stall!
How long the car engine continues running or how far you can drive largely depends on how long the car battery can continue powering the car’s electrical system which in turn depends on:
- whether the car’s battery is fully charged or otherwise
- how fast the car’s electrical system drains the battery power. You can extend how long the battery lasts by switching off non-essential electrical accessories. For example, the sound system or the fog lights!
The effect of not having a working alternator
The alternator charges and keeps the battery topped up. Without a working alternator, you can only drive the car for as long as the car battery still has charge.
Do You Need an Alternator to Drive
No, you do not need the alternator to start or drive the car provided the car battery is charged. That said, you’ll only be able to drive the car for as long as the battery still has enough power to keep the car’s electrical system running.
You can extend how long the battery lasts by switching off non-essential electrical accessories such as:
- the car’s sound system
- GPS navigation systems
- heater (depending on your situation)
- rear window defroster
Even then, there is power drain from the battery when the engine starts, powering fuel management systems, and from loads of sensors in modern cars, so the battery can only last so long.
2. How Far you Can Drive Without an Alternator?
You’ll only be able to drive as far as the battery is able to power the car’s electrical system. Ultimately, there’re several variables baked into this such as the battery capacity, whether it is fully charged or otherwise, and how quickly the car’s electrical accessories are drawing the battery power.
Want to drive for longer? Switch off the nonessential accessories.
Should you Run a Car without an Alternator?
It is risky to drive without a working alternator unless in case of an emergency and even then it should be for a short distance. You risk the car stopping in the middle of nowhere when the battery runs out.
So, contact a qualified mechanic or call for a tow.
3. How Long a Fully Charged Battery Lasts without an Alternator?
You’ll only be able to drive for a duration (hours) as long as the battery is able to power the car’s electrical system. There’s no one set, standard duration.
Ultimately, there’re several variables baked into this such as the battery capacity, whether it is fully charged or otherwise, and how quickly the car’s electrical accessories are drawing the battery power.
You may want to read: 6 Reasons why your car battery power may be draining and how to fix them
4. Can you Start a Car without an Alternator?
Yes, you can start a car without an alternator – that may also mean the alternator is in place but the belt is not connected provided the battery has the minimum CCA’s to turn your car engine over.
The alternator is not necessary when the car’s starting. It is only used after the car has started to power the car’s electrical system and to keep the battery charged.
So, you’ll be able to start the car without a problem but can only drive for as long as the battery remains charged!
5. How Many Times you Can Start a Car Without an Alternator
Unfortunately, there’s no one answer as it depends on the battery’s capacity and state of charge which may be different for your situation.
That said, the car starter can draw several hundred amps from a car battery albeit for a short time when the car is starting. Therefore, you can easily drain a car battery by making repeated start attempts.
Final Thoughts
You should only run your car without an alternator in an emergency. Once the battery power is used up, the car engine stops.
You can have your car running for longer by switching off non-essential accessories – or running your car when you do not need the high drain loads like the headlamps, and blower motor. But even then, know that you can only run it for a limited time.
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