Car Battery Voltage Chart Guide

What’s your car without a proper functional battery? Your vehicle will not even start without a battery, usually a 12V battery for most modern cars. Why does the battery’s voltage matter? The car battery voltage helps us to understand the amount of power it holds to run the engine and other electrical components in the car. Different car batteries have varying voltage levels, and it is crucial for every car owner to understand the battery they are using. This all-inclusive guide presents various car battery voltage charts for different battery types, including LiFePO4, AGM, Lead-Acid, and Deep-cycle.

What is Battery Voltage?

Car battery voltage refers to the electrical difference between the positive and negative terminals. It shows the amount of energy present to crank the engine and provide power to other electrical components in the car. There are several battery types, each with varying voltage levels depending on the chemical composition.

Most modern cars run on 12-volt batteries. However, electric vehicles (EVs) have high-voltage battery systems ranging between 400V and 800V, depending on the model. The optimal voltage ensures the battery can deliver enough power to ignite the engine. When the car engine is not running, the battery can provide a voltage ranging from 12.4V to 12.7 under normal circumstances. If the battery falls below 12.4V, it’s an indication that it is slowly dying or not fully charged. When the car engine is turned on, the normal operational voltage range is 13.7 Volts to 14.7 Volts while being charged by the alternator.

Car Battery Voltage Chart

A battery is the powerhouse for every car, powering the engine and the electrical system. Various types of vehicles have distinct battery specifications to enable them to meet their operational requirements. For instance, some cars only require 12V batteries for starting and lighting. Others, such as EVs, require 400V or more to support propulsion. Car batteries work at different voltages depending on the type of car and the electrical system.

The following car battery voltage chart demonstrates various car battery types and voltages.

12V Lead-Acid	12V AGM	12V LiFePO4	State of Charge
12.7	12.8+	14.4	100%
12.5	12.7	13.4	90%
12.42	12.5	13.3	80%
12.32	12.35	13.2	70%
12.2	12.15	13.1	60%
12.06	12.05	13.05	50%
11.09	11.95	13	40%
11.75	11.81	12.9	30%
11.58	11.66	12.8	20%
11.31	11.51	12.0	10%
10.5	10.5	10	0%

LiFePO4 Battery Voltage Chart

Lithium iron phosphate batteries have overtaken all other battery types in popularity due to their safety, longevity, and fast charging rate. Their high depth of discharge enables them to perform optimally even under extreme temperatures.

The LiFePO4 Battery Voltage chart below shows the State of Charge (SoC) for various voltages, i.e., 12V, 24V & 48V.

Capacity	12V	24V	48V
100%-Charging	14.6V	29.2V	58.4V
100%-Resting	13.6V	27.2V	54.4V
99%	13.4V	26.8V	53.6V
90%	13.3V	26.6V	53.2V
70%	13.2V	26.4V	52.8V
40%	13.1V	26.2V	52.4V
30%	13.0V	26.0V	52.0V
20%	12.9V	25.8V	51.6V
17%	12.8V	25.6V	51.2V
14%	12.5V	25.0V	50.0V
9%	12.0V	24.0V	48.0V
0%	10.0V	20.0V	40.0V

Lead-Acid Deep Cycle Battery Voltage Chart

The voltage of lead-acid batteries varies depending on factors such as battery type, e.g., flooded or sealed, discharge rate, and temperature. Sealed lead-acid batteries are low maintenance and require minimal ventilation, unlike flooded lead-acid batteries, which need more maintenance and ventilation.

Lead-acid batteries have been used for decades due to their affordability and availability. They sufficiently deliver large bursts of energy required for cranking the engine. However, they have a short life span and low energy density compared to other battery types.

Capacity	6V Sealed Lead-Acid Battery	6V Flooded Lead-Acid Battery
100%	6.44V	6.32V
90%	6.39V	6.26V
80%	6.33V	6.20V
70%	6.26V	6.15V
60%	6.20V	6.09V
50%	6.11V	6.03V
40%	6.05V	5.98V
30%	5.98V	5.94V
20%	5.90V	5.88V
10%	5.85V	5.82V
0%	5.81V	5.79V

Lithium-Ion Battery Voltage Chart

Lithium-ion batteries are commonly used to power handheld devices and modern electronics. Also, they are used in solar systems and power stations, although LiFePO4 is overtaking them. They perform better and have enhanced safety features than traditional lead-acid batteries. The voltage sizes for Li-ion batteries are 12V, 24V, and 48V.

Capacity	1 Cell	12V	24V	48V
100%	3.40	13.6	27.2	54.4
90%	3.35	13.4	26.8	53.6
80%	3.32	13.3	26.6	53.1
70%	3.30	13.2	26.4	52.8
60%	3.27	13.1	26.1	52.3
50%	3.26	13.0	26.0	52.2
40%	3.25	13.0	26.0	52.0
30%	3.22	12.9	25.8	52.5
20%	3.20	12.8	25.6	51.2
10%	3.00	12.0	24.0	48.0
0	2.50	10.0	20.0	40.0

Deep Cycle Battery Voltage Chart

Deep cycle batteries provide steady power for extended periods. They discharge steadily up to a low SoC and then recharge again. They are suitable for applications requiring consistent energy output, such as EVs and solar energy systems. They require minimal maintenance and have a longer life cycle than FLA batteries.

The following is the deep cycle battery chart for 12V, 24V, and 48V.

Capacity	12V	24V	48V
100% (Charging)	13.00V	26.00V	52.00V
99%	12.80V	25.75V	51.45V
90%	12.75V	25.55V	51.10V
80%	12.50V	25.00V	50.00V
70%	12.30V	24.60V	49.20V
60%	12.15V	24.30V	48.60V
50%	12.05V	24.10V	48.20V
40%	11.95V	23.90V	47.80V
30%	11.81V	23.62V	47.24V
20%	11.66V	23.32V	46.64V
10%	11.51V	23.02V	46.04V
0%	10.50V	21.00V	42.00V

Does the Cold Weather Kill Your Car Battery?

Not necessarily. However, car battery failure is more prevalent during winter. During cold seasons, the car’s battery performance and capacity drop to 30 up to 60%.

Batteries rely on chemical reactions from within to generate power for your car’s engine and electrical system. The chemical reaction is sensitive to extreme temperatures. Freezing temperatures slow down and can stop the reaction. Low temperatures minimize the kinetic activity within the battery.

However, proper maintenance, regular checkups, and good charging practices during cold weather will keep your battery running optimally throughout winter.

Voltage and Charging Systems

Battery voltage can impact charging systems. Higher-voltage batteries provide an avenue for efficient power delivery and charge faster because minimal current is needed for a similar amount of power.

Discuss The Role of Alternators and Voltage Regulators in Maintaining Proper Voltage

The alternator charges the battery as you drive your car. Also, it transmits electricity to the car’s electric system. It monitors and converts the engine’s mechanical energy into electrical energy, thus keeping the voltage within the required range. If the alternator malfunctions, it causes overheating and a decrease in voltage, which is harmful to the health of your battery.

The voltage regulator supports the alternator in maintaining proper voltage. It ensures a stable electrical output while safeguarding the car’s electrical system. The regulator provides the alternator that generates the correct voltage to power the electrical components.

Voltage regulators help maintain stable electrical output and protect the electrical system from voltage spikes and overcharging. They regulate the voltage, compensate for temperature variations, detect faults, prevent undercharging and overcharging, and ensure the optimal performance and longevity of the alternator. Generally, the regulator provides the reliability of your vehicle's electrical system.

Relationship Between Charging Voltage and Battery Health

To maintain optimal battery health, you must understand the relationship between the charging voltage and battery well-being and performance. Overcharging or deep discharging of the battery will cause faster degradation.

The battery charging voltage and the charging devices significantly determine a battery's health, performance, and longevity. The charging voltage varies depending on the battery type. For instance, the charging voltage for lithium-ion batteries is 3.6 to 4.2 volts, while the lead-acid battery's is 2.25 to 2.45 volts.

The following is a charging voltage chart for 12V Lithium-ion and LiFePO4 batteries.

State of charge	Lithium-ion Voltage	LiFePO4 Voltage	Charging Current
0%	10.0V	11.0V	Constant current: 20A Max
10%	11.1V	12.0V	Constant current: 20A Max
20%	11.6V	12.4V	Constant Current: 20A Max
30%	12.0V	12.8V	Constant current: 20A Max
40%	12.3V	13.0V	Constant voltage: 10-15A Tapering
50%	12.6V	13.2V	Constant voltage: 5-10A Tapering
60%	12.9V	13.4V	Constant Voltage: 2-5A Tapering
70%	13.2V	13.6V	Constant Voltage: 1-2A Tapering
80%	13.5V	13.8V	Constant Voltage: 0.5-1A Tapering
90%	13.8V	14.0V	Constant Voltage: 0.1-0.5A Tapering
100%	14.0V-14.4V	14.2V-14.4V	Float Voltage: 0.05A or Less

Final Thoughts

Understanding the car battery voltage chart lets you know your battery’s usability, performance, safety, and lifespan. Understanding the voltage characteristics of various types of batteries helps you choose the correct car battery and ensures safe operation. Knowledge of voltage charts is indispensable for any car owner keen to uphold battery safety. Renogy car batteries are multifunctional and require minimal maintenance.

FAQs About Car Battery Voltage Chart

1. What are the signs of low voltage car battery?

Some indications of a low-voltage car battery are dimming headlights, problems starting the engine, and an inability to power electric devices. Other telltale signs of a battery with voltage issues are the need for jumpstarts and electronic malfunction.

2. When is the battery considered damaged due to low voltage?

When a battery's voltage falls below the required threshold, it means the battery is damaged and needs replacement. If a 12V battery falls below 10.5V under a load, it’s a sign that the battery is obsolete and requires replacement. Consistent low voltage readings indicate that you need to replace the battery.