Every car has the “holy trinity” – the battery, starter, and alternator – which makes up your car’s electrical system. A battery powers the starter. The alternator provides the battery with the required energy to operate your vehicle while running. Can your car run without a battery, and is it wise to do so?
A car can run without a battery; however, a battery is required for a car to start. Technically, you can start a car and then remove the battery; the alternator will continue to provide power to the car. However, it’s not recommended since voltage spikes pose a major risk to all electrical components.
When either one of your car’s battery, starter, or alternator fails, your vehicle will not run as it should. The battery has the very important job of starting up your car and spreading electrical surges to your car’s electronics safely. Maintenance of your battery is vital in ensuring that your car doesn’t have to run only on the alternator at some point in its life.
Can A Car Run Without A Battery?
Your car can run without a battery, but only if the engine is running before the battery is removed or ‘’dies”. The battery provides stored energy to the starter motor and the ignition coil for engine starting. Hence you can’t start a car without the battery.
As a result, if the battery is disconnected from the car before the engine is started, you will be unable to get your car to run in the first place.
If you have already started your car and removed the battery, the car will run since the alternator has begun generating electrical energy. The ignition system uses the electrical energy generated by the alternator to generate sparks. The engine will continue to run as all electrically driven accessories are now powered by the alternator.
Hypothetically speaking, if your car is running and you remove the battery, you will be able to drive until you switch off the engine. However, if the electrical demand is too heavy, the engine may cut off, and you won’t be able to restart your car without a functional battery.
How Does A Car Run Without A Battery?
A car can only run without a battery when fitted with a functioning alternator. The alternator, powered by the engine’s serpentine belt, provides power (electrical current) to your vehicle during normal operation, transferring energy to your car’s battery, which acts as a storage unit, and a surge protector for the overall electrical system.
If your car is running without a battery or a dead battery, the following will occur underneath your car’s bonnet:
- The alternator will try and do its job of charging the battery to its maximum load, putting out different currents to ensure it stays charged.
- Normally, when the alternator feels the battery’s energy level is where it should be, it will send out little trickles of current to keep the battery topped up.
- Should the alternator find that the battery has a low charge or that the energy inside the battery is getting low, it will pump out more amperage to try and bring the levels up.
- When your alternator doesn’t find a reference point from the battery (in the case of the battery being removed or dead), it will start sending out maximum current when it realizes that it needs to do all the work now.
- The alternator will push out currents at different voltages at different RPMs and different speeds, causing massive spikes in voltage as it tries to keep up with the energy demands of your vehicle – which isn’t currently being converted into a steady flow of current as it has no battery to perform surge protecting duties.
- Without the battery, the voltage sent from the alternator will differ and spike so that it can negatively impact any of your car’s electronics.
When you start adding to the load by turning on the aircon, the radio, wipers, lights, indicators, and electric windows, it will lead to dramatic spikes in the current that can lead to the engine cutting out as the alternator struggles to keep up with the car’s electrical demand.
Why Do You Need A Car Battery?
Until your car starts, your battery supplies the full electrical current to the vehicle, including the current to the starter and fuel systems that are in charge of producing the combustion required for your engine to run.
After the engine has started, the alternator generates an electric current that replaces the energy drawn from the battery by the starter. As the engine transforms the electrical energy into mechanical energy, the alternator recharges the battery constantly.
The battery is also a surge protector, taking the spiking surges the alternator sends and spreading them in a steady voltage source to the required electrical components. Your battery also serves as a backup power source. When your car consumes more electricity than the alternator can generate, it will draw power from the battery to make up the difference.
When your car draws backup power from the battery too frequently or too long, you risk emptying the battery because the alternator cannot keep up with recharging the battery.
Will A Car Stop Running If The Battery Dies?
Depending on the health of your car’s alternator, your car should be able to continue running when the battery dies. As long as your car engine is running, and if your car’s alternator is able to generate enough energy for all electrical components requiring a charge, the car will keep on running.
The key to keeping your car running without a battery is to turn off high-energy components like the aircon and sound systems, to lessen the load of the required electrical power that your alternator now has to produce all by itself.
If your car’s alternator is not in the best of shape, it may struggle to power the whole car. You might find that when coming to a full stop, the car will indicate that it’s about to cut out, as alternators work best when the engine is running and not when it idles.
Before the complete shutdown occurs, you may want to put the car in neutral and generate extra power by revving the engine. As mentioned, when the battery is dead and the car is not running, you will have to use alternative methods to start the vehicle up again.
Can You Start a Car Without a Battery?
You can start a car without a battery. There are a couple of ways to do this, but the most common method is called push-starting, commonly referred to as “popping the clutch” or “bump starting,” typically used with cars with a manual stick. Other methods include using jump boxes and jump-starting.
How to Start a Manual Car Without a Battery?
The easiest way to start a manual transmission car is by push-starting it. This method works well with cars that are fitted with a mechanically driven alternator and an internal combustion engine.
Here’s how you push start a manual car:
- Switch the ignition to on/run, put the car in second gear, and depress the clutch. Ideally, you would do this on a downhill to obtain the required speed (10 mph normally does the trick), but the car can also be pushed physically on a straight road.
- When your car is at a fast enough speed, let the clutch go to allow the engine to rotate and start, while putting some pressure on the gas pedal.
- When the car starts, give it some gas and drive away.
The other method to start a manual car without a battery is by using a jump box. A jump box is a small portable battery with attached jumper cables.
The software found in these boxes prevents voltage spikes that can potentially cause havoc on your car’s electrical system. Most of these inexpensive jump boxes are fitted with USB ports, safety lights, and AC outlets.
Click here for a helpful tutorial on how to use a jump box in the correct manner.
How to Start an Automatic Car Without a Battery?
If you own an automatic car, and its battery decides to drop you like a bad habit next to the road, you are going nowhere slowly.
Automatic cars cannot be push-started; these that can are too few to mention, so that leaves you with getting a jump start from another car, using jumping cables, or jump-starting your corpse of a car by using a jump box.
Click here to view a tutorial on how to jump-start a car in a safe and easy manner.
Signs That You Need To Replace Your Car Battery
Without a functioning battery, driving your car will become a nightmare. It’s no fun when your car stalls at a traffic light and refuses to start. Life’s tough as it is; no need for extra drama. Here are possible signs that your car battery might need replacing:
- Your car engine is slow to turn over
- Any electrical issues
- “Check” engine light comes on
- A rotten egg smell under the hood
- The battery’s connectors are corroded
- The battery case is misshapen
- Your battery is old – batteries often last 3 to 5 years only
Suppose you are noticing any of the above, head to your local automobile business and get your battery checked out by a professional. If it’s not the battery, the friendly staff will automatically check your alternator as the next point of reference.
Tips On Prolonging Your Battery’s Life
Discharge-recharge reactions occur loads of times during the life of a battery. Each cycle wears out the plates slightly, and the lead deteriorates with time. Cold-cranking amps drop when the capacity of your car battery degrades.
Keeping your battery functional for as long as possible is the way to go, and here are some helpful tips to ensure you get the most out of the little powerhouse:
1. Avoid Deep Discharging Of The Battery
When you power lights, audio, and other electrical equipment while your car’s engine is off, you actively draw power from your car’s battery. It’s called deep discharging and accounts for many battery failures.
Using your battery in the above manner for a long period and then recharging it through driving may cause the sulfur in the electrolyte solution to bind to the lead and cause further damage to the battery’s plates. Try not to use the electronics in your car when the engine is off.
2. Ensure Your Car Battery Is Secured Tightly
Check your battery terminal regularly, especially if you drive on bumpy roads, to ensure it is tightly and securely positioned in the mounting bracket. A loosely connected battery may shake, potentially causing internal damage and short circuits.
3. Control The Corrosion
Battery terminals degrade over time, but keeping them clean and free of debris is an excellent method to increase the life of your car’s battery. Scrub the terminals with a toothbrush dipped in water and baking soda. Rinse the mixture with cold water and use a dry cloth to clean the terminals.
4. Take Regular Long Drives
Battery power is maintained when you drive your car often and for long periods. Short and irregular driving habits prohibit the battery from fully charging. If you don’t drive regularly and only for short stints, do your car battery and take the longer scenic route now and again.
If there’s a reason that you can’t undertake longer rides, then purchasing a portable auto battery charger is a smart move. In the event that you become stuck, you’ll be able to jump-start your battery without the need of a good Samaritan.
5. Test The Battery Regularly
Knowing the status of your car battery is important if you want to extend its life. Using a car battery tester, check the output voltage level of your battery to see how well you’re maintaining it and if it’s time for a replacement.
For example, if your car is fitted with a 12-volt battery, the battery voltage can range anywhere from 12.6 (when the engine is off, known as ‘resting voltage’) and 13.5 to 14.5 when the engine is running. The higher levels are due to the battery being boosted by the alternator.
6. Get Your Battery Inspected
A good maintenance habit regarding your car battery is to get it inspected every 6 months or 6,000 miles. Being proactive will save you from standing beside the road with a ‘dead’ battery, powerless and frustrated.