Check your battery condition by using car battery voltage


You can avoid a car battery death by keeping your battery in good shape. A simple check of the battery voltage will help you determine the battery’s current condition and whether you need to do any maintenance.

This article will show you how to test voltage for Lithium-Iron Phosphate, Absorbed Glass Mats (AGM), and lead-acid batteries.

What Voltage is a Car Battery? 

Definition of Battery Voltage 

Simply measuring the battery voltage, you can get an idea of the battery’s condition. To detect potential problems and prevent them from getting worse, you can monitor the battery’s voltage.

Car Battery Voltage Chart

Your car’s electrical system uses 12 volts, so your car battery needs to supply between 12 and 13 volts for it to operate correctly. The voltage will decrease as the battery is removed. How much? VoltageThe type and brand of the battery will determine how much drop you get.

12V lead-acid/AGM/LiFePO4 battery voltage table chart

car battery voltage chart

Voltage Chart Lead Acid Batteries

Voltage of Lead Acid Batteries at Rest (Engine Off).

State of chargeVoltage of lead-acid battery

Voltage chart for 12V Lead-acid batteries

Voltage chart for 12V Lead acid Batteries

12.6 volts or more A voltage reading of more than 12.6 volts indicates that your battery is fully charged. There is nothing to be concerned about.

12.5 volts: A reading of 12.5V indicates that your battery is healthy and has 90% charge. If you only took a short drive, the alternator may not have had enough time to charge your battery. Make sure to check the voltage after a long driving trip.

12.3 – 12.4 volts: The battery should be at 75% charge and must be charged to that level. It is recommended to use a battery charger and not rely on your car’s alternator.

12.1 – 12.2 volts: The charge level for this battery is approximately 50%. It is important to immediately connect a battery charger.

12 volts and lessCharging your battery at 12 volts, or less, can cause damage. This could cause it to last less time. It is essential to immediately connect a charger.

You can order a smart charger online.

When the Car Starts

Your battery’s primary function is to start your engine. This is also the biggest drain. Voltage can drop when there is a lot current flowing when your engine runs. About nine to ten Volts.

Once the engine is started, it should quickly return to normal voltages.

Voltage of Lead-Acid Batteries When The Car Is Runnin’

The alternator charges your car’s battery while it is running to avoid overcharging. It is controlled via a regulator. The voltage at its terminals should be Between 13.7 and 14.7 Volts.

Voltage Chart Absorbed Mat Battery

AGM batteries can be purchased here lead-acid batteriesThey have superior power characteristics to the standard flooded acid battery type.

Although the voltage readings are comparable to lead-acid, they may be 0.2 Volts higher at certain charge level.

tate of Charge Voltage of AGM batteries

Voltage chart for 12V AGM batteries

Voltage chart 12V AGM batteries

Chart showing the voltage of lithium iron phosphate batteries 

LiFePO4 batteriesFlooded lead-acid battery technology uses a different technology and the voltage levels across this range are significantly higher.

When fully charged, a LiFePO4 lithium battery will have a voltage around 14.4 volts. This voltage will decrease slightly when the charger is removed. It is fully charged when the battery voltage reaches at least 13.6 Volts.

State of charge Voltage of lithium battery 

Voltage chart for 12V LiFePO4 lithium-ion battery

Voltage chart for 12V LiFePO4 lithium ion battery

What Voltage should a car battery be replaced?

Before you check the voltage, ensure that the battery is fully charged. Once the battery is fully charged, you can check the voltage. While it may appear that everything is going well, it can be dangerous if the voltage drops quickly.

A low voltage reading of less than 12 volts is usually a sign that the battery is dead or damaged. It is time to replace it if it falls below 10.5 volts.

How to Test Car Battery Voltage

Using a voltmeter or multimeter is a simple task to check a battery’s condition.

To test the battery voltage, there are three steps: Turn off your engine, turn the multimeter/voltmeter DC voltages on, then compare the voltage result with the information above.

Step 1: Prepare your Battery

Before you take the measurement make sure that your engine is off and the battery is removed from your charger.

Step 2: Set Your Multimeter/Voltmeter To DC Volts

Set the multimeter/voltmeter in DC volt range to read more than 20 volts. Connect the red (+), lead to the positive battery terminal, while the black (-), lead to the negative terminal.

Step 3: Measure the Voltage

Take note of the voltage reading and compare it to the information above.

Multimeters are available here

Is there a better way?

Another option is to take your battery to a mechanic who will test it using a load tester.


Every day, we depend on our car’s battery to start the car. However, batteries will eventually run out and become inoperable.

By checking your battery’s voltage regularly and maintaining it in good condition, you can get the best out of it. This is a simple task any homeowner can do that will save money in long-term.


What is the 12-Volt Battery’s Full Charge?

These voltage measurements should be available for 12-volt batteries that have been fully charged. These voltages are common after a fully charged battery has been charged. “rest”Before taking the measurement, wait for the battery to charge for a few hours.

  • Lead-Acid/AGM – around 12.6 to 12.8 volts
  • LiFePO4 – around 14 volts

What Car Battery Voltage is Too Low for?

A car battery’s primary purpose is to start the engine. It requires a lot of power. It is important that your car battery be charged at least to 100 percent. Your lead-acid battery can be damaged if they are left uncharged, or if they are plugged in at less than 12.5 volts.

LiFePO4 batteries have a different internal chemistry. They should not be dropped below 12 volts.

When is it time for your car’s battery to be replaced?

The type of car battery you have will determine the voltage at which it should be replaced. If a lead acid battery is fully charged but the voltage measurement is still below 12 volts, it is almost dead.

After charging LiFePO4 lithium batteries, it is recommended to have a voltage of around 14 volts

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Check your Battery Condition Using Car Battery Voltage

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