Car Battery Reads 13 Volts But Won’t start -What To Do -2024

I recently encountered a frustrating situation with my car – the battery was reading a solid 13volts, 13.3v, 13.5, and 13.6, yet the engine refused to start. It was a perplexing scenario, and I knew I had to delve into the problem to find a solution.

Battery charged but no cranking power? (Short Answer)

There might be a problem with the alternator, possible that there’s a fuel delivery issue, weak battery, parasitic drain, corroded battery terminals, or other electrical issues that can cause this problem.

This scenario prompted me to investigate the root causes and find a quick resolution. Let’s delve into the potential reasons behind this issue and simple solutions to get your vehicle back on the road.

Reasons Behind Car Battery Reads 13 Volts But Won’t Start:

In my recent experience, I faced the frustration of a car battery showing a seemingly sufficient 13 volts but failing to start the engine. When confronted with a situation where the car battery reads 13 volts but won’t start, several potential reasons may be at play.

 Car Battery Reads 13 Volts

1. Dead Or Weak Battery:

Battery charged but no cranking power? A battery that reads 13 volts can still be weak or dead. I faced a situation where the battery displayed a seemingly respectable 13 volts, leading me to believe it was in good condition.

The battery’s voltage indicates the charge’s state but does not reflect its ability to deliver the required current to start the car. Despite reading 13 volts, a weak or dead battery won’t have enough power to start the engine.

Also Read: Car Battery Making Hissing Noise

2. Corroded Battery Terminals:

Corroded battery terminals can prevent the battery from delivering the required current to start the engine. Exposure to water or additional outside factors can cause corrosion.

Corroded Battery Terminals

The corrosion can cause resistance, preventing the battery from delivering enough current to start the engine, even if the voltage exceeds 13 volts.

3. Faulty Alternator:

My car battery reads 13 volts? The alternator is responsible for charging the battery while the car is running. A defective alternator may not charge the battery sufficiently, leaving it with a low charge. The battery may register 13 volts when the engine is running, but it is insufficient power to start the vehicle.

4. Parasitic Drain:

A parasitic drain is an electrical load on the battery when the car is turned off. The cause could be an electrical component that isn’t working correctly or an electrical short in the car.

 Parasitic Drain

The parasitic drain can cause the battery to discharge, even when the car is not in use. If the battery empties when the car is not in use, there won’t be enough power to start the engine.

Also Read: How To Fix Reverse Polarity On A Car Battery

5. Starter Motor Problems:

The starter motor turns the engine over when the key is turned. A broken starting motor may prevent the engine from turning over even if the battery has enough juice. It may occur due to wear and tear or a defective solenoid.

Resolving The Issue When Car Battery Reads 13 Volts But Won’t start:

In tackling the frustrating scenario of a car battery reading 13 volts but refusing to start the engine, my journey toward a solution involved a systematic approach.

Recognizing that the voltage alone wasn’t a comprehensive indicator of the battery’s health, I delved into potential causes and effective resolutions.

First thing to do is check the battery. A fully charged battery must have enough cranking capacity to provide the starter motor and ignition system with enough power to start the engine over a broad range of ambient temperatures

Car Battery Reads 13 Volts

1. Check Battery Terminals:

Check the battery terminals for corrosion or loose connections. Clean the terminals with a wire brush or terminal cleaner to remove any corrosion. Tighten any loose connections to ensure a good connection.

2. Check Alternator:

If the battery terminals are clean and tight, check the alternator. Measure the alternator’s voltage output using a multimeter. It should read between 13.8 and 14.5 volts. Low voltage output could indicate a malfunctioning alternator that requires replacement.

 Check Alternator

Also Read: How Long Will A Car Battery Last Without An Alternator

3. Check For Parasitic Drain:

To resolve the issue car battery is fully charged but with no power, disconnect the negative battery cable and connect an ammeter in series with the battery terminal to check for a parasitic drain.

The ammeter should read less than 50 milliamps. The battery may have a parasitic drain if the ammeter reads more than 50 milliamps.

To identify the source of the drain, start removing fuses one by one and monitor the ammeter. When the ammeter reading drops, the circuit with the drain has been identified.

4. Check Starter Motor:

First, check the starter motor and ensure the battery is fully charged. The starter motor may be damaged if the battery is fully charged, yet the engine won’t start.

Using a multimeter to measure the voltage at the starter motor’s terminals while someone turns the key, you can check the starter motor using a multimeter. The starter motor may need to be replaced if there is voltage, but the motor is not turning.

Check Starter Motor

Car won t start but battery is good? The most typical reason for a car that won’t start even though the battery is good is a bad starter, though it could also be a gasoline issue. It’s possible that you don’t have enough gas to start the automobile.

Also Read: How Long Does It Take To Change A Car Battery

Battery charged but no cranking power:

Assuming the battery is in optimal condition, my exploration led me to consider various factors, primarily focusing on the connections between the battery and the starter motor.

One common culprit that can impede the flow of power is dirty, corroded, or loose connections. I embarked on a meticulous examination of the battery terminals and the wiring leading to the starter motor.

Any buildup of dirt or corrosion on the terminals can create resistance, hindering the efficient transfer of power.

In my case, I discovered that over time, a combination of environmental factors and normal wear and tear had contributed to the corrosion on the battery terminals.

Battery Says Charged But Won’t Start:

How many volts does a car battery need to start? The voltage of a fully charged automobile battery should be close to 12.6 volts.

There’s a chance the battery won’t have enough juice to start the automobile if the voltage falls below 12 volts. A battery with a voltage of at least 12.4 volts is advised to guarantee a dependable start. Battery reads 12.6 volts but wont start is due to:

  • Failing Battery: The battery shows fully charged but car won’t start, check all fuses and check the battery with a voltmeter. These elements may make it less able to deliver enough power to start the engine.
  • Dead Cell: A single dead cell in a battery can lower the voltage and capacity of the entire unit, rendering it incapable of supplying the necessary power for starting.
  • Fuel Pump: The fuel pump is in charge of supplying the engine with fuel from the tank. If it malfunctions, the engine might not get the fuel pressure needed for ignition.
  • Ignition Switch: A broken ignition switch might prevent the starter from getting the go-ahead, making starting more difficult.
  • Battery Cables: Corroded or broken battery cables may cause voltage drops and obstruct the starter’s ability to receive the required electrical current.
  • Starter: To start the engine, the starter motor turns the flywheel. Even if the battery is in good condition, a bad starter can cause the engine not to start.
Source: quora

So, these are the reasons of battery charger says fully charged but car won’t start.

Car Wont Start Without Jump? It appears to be a battery issue if you have a new battery but the car still won’t start without a jump start. Your diagnosis or gut feeling to change the battery may have been correct. However, the issue will not be resolved if the battery is put in improperly.

Car battery 13 volts when running? A healthy car battery will show values between 13 and 15 volts when you test it while the engine is running.

After a long drive, the voltage output may register between 12.4 and 12.9 volts if your battery is ultimately charged.

Car battery reading 13.6 volts? The alternator charges the battery when the engine is running, and its voltage should be between 13.7 and 14.7 volts. The alternator recharges the battery if it is below 13.6–13.7 volts; remember, this happens while the engine is switched ON and the battery is being charged.

13.1 volts car battery? Most car batteries should measure at least 12.6 volts when fully charged (13.0–13.32 volts for OPTIMA YELLOWTOPs), although low voltage doesn’t always indicate a faulty battery. Modern cars are electrically demanding even when they are not in operation.

Relevant Questions:

1. Can a car battery have good voltage and still be bad?

Yes, a car battery can display the correct voltage reading while still in poor condition. This situation arises when the battery’s internal resistance becomes excessively high, causing the voltage to drop significantly under a load. In such cases, Time to Replace it.

2. Are 13 Volts Enough To Start A Car?

Is 13 volts enough to start a car? 13 volts is not necessarily enough to start a car. While it indicates the battery is charged, it may not have enough cranking power to turn the engine over. Factors like battery age, temperature, and electrical system parts can also affect the car’s ability to start.

3. Is 13v Too High For A Car Battery?

No, 13 volts is not too high for a car battery. It is a standard voltage reading for a fully charged battery when the engine is off. However, a reading of 13 volts alone does not indicate the battery’s ability to start the car, as other factors, such as internal resistance and cranking power, must also be considered.

4. Why Is My 12V Battery Showing 13v Car Battery?

12 volt battery reading 13 volts? A 12V battery reading of a car battery at 13 volts indicates the battery is fully charged. The voltage can increase slightly when the battery is disconnected from the charging system, and the surface charge decreases. 13.3-volt car battery? There might be a problem with the alternator.

5. Is 13 Volts Good For A Car Battery?

Is 13.3 volts a good battery? Yes, 13 volts is a suitable battery voltage. It indicates that the battery is fully charged and the system functions correctly. However, the voltage reading alone does not guarantee the battery’s health and ability to start the car. Other factors, such as internal resistance and cranking power, must also be considered.

6. Car Battery Reading 14 Volts But Won’t Start?

The battery is standard if the voltmeter reads between 14-15 volts. Unfortunately, despite the voltmeter giving a good reading of 14 volts, the automobile is not starting as it should. While a voltage reading between 14 and 15 volts typically indicates a healthy battery, the starting problem could also be caused by other underlying issues.

7. Is 13.8 V Enough To Charge Battery?

Car battery 13.8 volts? Yes, 13.8 volts is enough to charge a battery, but it may only be best for some types of batteries. Different batteries have different charging requirements, and following the maker’s recommendations is essential.

8. Battery Has Voltage But Won’t Start Car?

Your battery’s internal resistance may be significantly higher than it should be because it is old or damaged. The terminal voltage can drastically decrease when the starter motor attempts to draw hundreds of amps, for example, down to maybe 8 volts, and won’t drive the current that the starter motor needs.

9. car battery shows 12 volts but wont crank?

Battery reads 12.4 volts but won’t start? A car battery with 12 volts is considered low and may not be fully charged or capable. A fully charged battery should have a reading of about 12.6–12.8V. Low voltage may make it difficult to start the car and may indicate that the battery needs to be charged or replaced.

10. 12v battery reads good voltage but No AMPS?

Encountering a 12-volt battery with a seemingly good voltage reading but no available amps can be a perplexing situation. While the voltage indicates the electrical potential, the absence of amps implies a lack of current flow, crucial for powering the vehicle’s electrical components and starting the engine.


Concluding my journey through the perplexing challenge of a car battery displaying a seemingly healthy 13 volts but refusing to start, it’s clear that multiple factors contribute to this frustrating scenario. Drawing from my own experience, I encountered the possibility of a weak or dead battery, corroded terminals, a malfunctioning alternator, a parasitic drain, or issues with the starter motor. To address the problem effectively, I realized the importance of a step-by-step approach, systematically checking and resolving each potential cause.

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