Battery Charger Voltage Chart: Li-ion, LiFePO4 & Lead Acid

Choosing the correct battery charger voltage is essential for safe, reliable, and efficient battery charging. A charger with the wrong output voltage may cause a battery to charge incorrectly, reduce battery life, trigger battery protection, or create a safety risk.

Battery voltage can be confusing because a battery may have a nominal voltage, while its required charger has a higher maximum charging voltage. For example, a 12V-class lithium-ion battery commonly uses a 12.6V charger. A typical 3S lithium-ion battery has a nominal voltage of approximately 10.8–11.1V but requires a 12.6V charger when fully charged.

This battery charger voltage chart provides a practical reference for common lithium-ion, LiFePO4, and lead-acid battery systems. It explains the relationship between battery nominal voltage, cell count, full-charge voltage, and charger output voltage.

For businesses sourcing battery chargers for products, equipment, mobility systems, energy storage, or battery packs, understanding these voltage relationships is also important when specifying a charger with a power supply manufacturer.

Quick Battery Charger Voltage Chart

The table below provides a quick reference for commonly used battery configurations.

Important: These values are general reference values rather than universal specifications. The correct charging voltage depends on the battery chemistry, cell configuration, manufacturer specifications, BMS requirements, charging method, and operating conditions. Always verify the battery manufacturer’s charging requirements before selecting a charger.

What Is Battery Charging Voltage?

Battery charging voltage is the voltage supplied by a charger to a battery during the charging process. It is normally higher than the battery’s nominal voltage because current must flow into the battery cells.

The key difference is between nominal battery voltage and maximum charging voltage.

For example:

• A 3S lithium-ion battery is commonly described as an 11.1V battery.
• Each conventional lithium-ion cell has a nominal voltage of approximately 3.6–3.7V.
• Three cells connected in series produce approximately 10.8–11.1V nominal voltage.
• Each cell can typically charge to 4.2V.
• Therefore, three cells require a maximum charging voltage of 12.6V.

This is why a product described as an “11.1V lithium battery” commonly requires a 12.6V battery charger, rather than an 11.1V charger.

The same principle applies to larger battery packs.

A 6S lithium-ion battery has a nominal voltage of approximately 21.6–22.2V and typically requires a 25.2V charger.

A 13S lithium-ion battery has a nominal voltage of approximately 46.8–48.1V and typically requires a 54.6V charger.

Understanding this distinction is one of the most important steps when choosing a battery charger.

Lithium-Ion Battery Charger Voltage Chart

Lithium-ion batteries are widely used in portable electronics, electric mobility products, battery-powered equipment, robotics, and other applications.

For conventional lithium-ion cells using a 4.2V maximum charging voltage per cell, the charger voltage can be estimated from the number of cells connected in series.

The basic relationship is:

Li-ion charging voltage = Number of cells in series × 4.2V

For example:

3S × 4.2V = 12.6V

6S × 4.2V = 25.2V

10S × 4.2V = 42.0V

13S × 4.2V = 54.6V

14S × 4.2V = 58.8V

Common Li-ion Charging Voltages

The exact nominal voltage depends on the specific lithium-ion cell chemistry and manufacturer’s specification, but the maximum charging voltage is commonly determined by the cell’s specified charge limit.

LiFePO4 Battery Charging Voltage

LiFePO4, or lithium iron phosphate, uses a different cell voltage from conventional lithium-ion batteries.

A typical LiFePO4 cell has a nominal voltage of approximately 3.2V and a full-charge voltage of approximately 3.65V.

The basic relationship is:

LiFePO4 charging voltage = Number of cells in series × 3.65V

For example:

4S × 3.65V = 14.6V

This is why a 12.8V LiFePO4 battery typically uses a 14.6V charger.

Likewise:

• 8S LiFePO4 → 29.2V charging voltage
• 12S LiFePO4 → 43.8V charging voltage
• 16S LiFePO4 → 58.4V charging voltage

This distinction is particularly important because a charger designed for conventional lithium-ion chemistry should not automatically be used with a LiFePO4 battery simply because their nominal voltages appear similar.

Common LiFePO4 Charging Voltage Chart

For a more detailed comparison between LiFePO4 and conventional lithium-ion charging requirements, see LiFePO4 Charger vs Lithium-Ion Charger.

Lead-Acid Battery Charger Voltage Chart

Lead-acid batteries follow a different charging method from lithium batteries. Their charging voltage depends on battery construction, charging stage, temperature, and manufacturer specifications.

Common lead-acid battery systems include 6V, 12V, 24V, 36V, and 48V configurations.

A typical 12V lead-acid battery may have a nominal voltage of 12V but require a charging voltage around 14.4V to 14.7V during the appropriate charging stage.

Similarly, a 24V battery system may require approximately 28.8V or a related voltage depending on the battery type and charging profile.

*Reference values only. Charging voltage varies by battery type, charging stage, temperature compensation, and manufacturer specifications.

Unlike lithium batteries, lead-acid charging should not be selected using only a simple “nominal voltage × fixed multiplier” rule.

Battery Nominal Voltage vs Charger Voltage

One of the most common battery charging mistakes is assuming that the battery label and charger output voltage should be identical.

They often are not.

Consider these examples:

Therefore, when sourcing a charger, the question should not simply be:

“What is the battery voltage?”

Instead, determine:

1. What is the battery chemistry?
2. What is the nominal battery voltage?
3. How many cells are connected in series?
4. What is the specified maximum charging voltage?
5. What charging current is required?
6. Does the battery have a BMS?
7. Does the charger need a specific charging profile?

These factors determine the correct charger specification.

How to Calculate Battery Charger Voltage

For many lithium battery packs, calculating the charger voltage is straightforward once the cell chemistry and series configuration are known.

For Conventional Li-ion

Use:

Charging voltage = Series cells × 4.2V

Example:

A 6S battery:

6 × 4.2V = 25.2V

Therefore, a 6S conventional lithium-ion battery typically requires a 25.2V charger.

For LiFePO4

Use:

Charging voltage = Series cells × 3.65V

Example:

A 4S LiFePO4 battery:

4 × 3.65V = 14.6V

Therefore, a 12.8V nominal 4S LiFePO4 battery typically requires a 14.6V charger.

Why Series Count Matters

Cells connected in series increase voltage.

For example:

• 1S = one cell
• 2S = two cells in series
• 4S = four cells in series
• 6S = six cells in series
• 10S = ten cells in series
• 13S = thirteen cells in series
• 14S = fourteen cells in series

Cells connected in parallel primarily increase capacity and available current rather than nominal voltage.

For example, a 4S2P battery pack still has the voltage characteristics of a 4S battery, while its capacity is increased by the parallel configuration.

Why the Correct Charger Voltage Matters

Using the correct charging voltage is essential for battery performance and safety.

1. Too Low a Charger Voltage

If the charger voltage is below the battery’s required charging voltage, the battery may not reach full charge.

For example, using an unsuitable lower-voltage charger on a lithium battery pack can result in:

• Incomplete charging
• Reduced usable capacity
• Longer charging time
• Charger or BMS compatibility issues

A charger that cannot reach the required charging voltage may stop charging before the battery reaches its intended state of charge.

2. Too High a Charger Voltage

A charger with an output voltage higher than the battery’s specified charging voltage can be dangerous.

For lithium batteries, overvoltage conditions can cause the battery management system to disconnect charging, and inappropriate charging conditions may damage cells or create serious safety risks.

Therefore, “higher voltage for faster charging” is not a valid approach.

3. Correct Voltage but Incorrect Chemistry

Two batteries can have similar nominal voltages but require different charging characteristics.

For example, a conventional lithium-ion battery and a LiFePO4 battery can both be described as approximately 12V-class batteries.

However:

• Typical 3S Li-ion charging voltage: 12.6V
• Typical 4S LiFePO4 charging voltage: 14.6V

The chemistry and cell configuration must therefore be identified before selecting a charger.

Battery Charger Voltage and Current Must Be Considered Together

Voltage is only one part of charger selection.

A battery charger is normally specified by both:

Output Voltage + Output Current

For example:

14.6V 4A

means:

• 14.6V charging voltage
• 4A maximum charging current

The approximate output power can be calculated as:

Power = Voltage × Current

Therefore:

14.6V × 4A = 58.4W

Similarly:

58.8V × 2A = 117.6W

58.8V × 5A = 294W

This is useful when selecting a charger platform because the voltage determines compatibility with the battery while the current determines how much charging power can be delivered.

For more information about charger current, see Battery Charger Current Explained.

Can You Use a Power Adapter as a Battery Charger?

A standard AC/DC power adapter and a battery charger may look similar from the outside, but they are not necessarily interchangeable.

A standard power adapter is generally designed to provide a regulated DC output to an electronic load.

A battery charger is designed around the charging requirements of a particular battery chemistry and charging process.

Depending on the battery system, the charger may need to provide:

• Controlled charging voltage
• Controlled charging current
• CC/CV charging
• Battery-specific charging behavior
• Protection functions
• Compatibility with the battery management system

For this reason, selecting a charger only by matching the DC plug and output voltage is not sufficient.

When a project requires a specific battery charging function, Guangdong QINX Technology Co., Ltd. (Guangdong QINX) can evaluate the required charging voltage, charging current, battery chemistry, connector, cable, input plug, form factor, and application requirements to determine an appropriate AC/DC charger configuration.

Common Battery Charger Voltage Examples

The following examples illustrate how battery voltage charts can be applied to real-world specifications.

Example 1: 12.8V LiFePO4 Battery

Suppose a battery pack is labeled:

12.8V LiFePO4, 20Ah

A typical configuration is 4S LiFePO4.

The charging voltage is:

4 × 3.65V = 14.6V

The charger specification may therefore be:

14.6V charger

The required current depends on the battery manufacturer’s charging specification and the desired charging time.

Example 2: 48V-Class Lithium Battery

A battery may be marketed as a “48V lithium battery.”

However, “48V” alone does not identify the charging voltage.

A common 13S lithium-ion configuration has:

13 × 4.2V = 54.6V

Therefore, a 13S lithium-ion battery commonly uses a:

54.6V charger

This is one reason 54.6V battery chargers are commonly specified for 48V-class lithium-ion systems.

Example 3: 58.8V Charger

A 58.8V charger is commonly associated with a 14S conventional lithium-ion battery:

14 × 4.2V = 58.8V

The corresponding nominal battery voltage is approximately 50.4–51.8V depending on the nominal cell specification.

However, a 58.8V charger should not automatically be used for every battery described as “48V” or “51.2V.” The battery chemistry and manufacturer’s specified charging voltage must be confirmed first.

Example 4: 25.2V Charger

A 25.2V charger commonly corresponds to a 6S lithium-ion battery:

6 × 4.2V = 25.2V

The battery’s nominal voltage is approximately 21.6–22.2V.

This configuration can appear in battery-powered equipment, portable equipment, mobility products, and other applications.

What Voltage Charger Do I Need?

To identify the appropriate battery charger voltage, follow this process.

Step 1: Check the Battery Label

Look for information such as:

• Battery chemistry
• Nominal voltage
• Capacity
• Maximum charging voltage
• Recommended charging current
• BMS information

Do not rely only on the “12V,” “24V,” “36V,” or “48V” label.

Step 2: Identify the Battery Chemistry

Determine whether the battery uses:

• Lithium-ion
• LiFePO4
• Lead acid
• Another chemistry

Different chemistries have different charging requirements.

Step 3: Identify the Series Configuration

For lithium battery packs, determine the number of cells connected in series.

For example:

• 3S Li-ion → 12.6V
• 4S LiFePO4 → 14.6V
• 6S Li-ion → 25.2V
• 10S Li-ion → 42.0V
• 13S Li-ion → 54.6V
• 14S Li-ion → 58.8V

Step 4: Confirm the Manufacturer’s Specification

The calculated value should be treated as a reference rather than a replacement for the battery manufacturer’s specification.

This is particularly important for customized battery packs, specialty cells, and applications with a dedicated BMS.

Step 5: Select the Charger Current

After confirming voltage, determine the appropriate charging current.

For example, a project may require:

14.6V 4A

rather than simply “14.6V.”

Both voltage and current are essential parts of the charger specification.

Common Battery Charger Voltage Mistakes

Mistake 1: Matching the Charger Voltage to the Nominal Battery Voltage

A 12.8V LiFePO4 battery typically does not use a 12.8V charger.

The charger needs to reach the battery’s specified charging voltage, commonly 14.6V for a 4S LiFePO4 configuration.

Mistake 2: Assuming Every “48V Battery” Uses the Same Charger

A 48V-class battery can have different cell configurations and chemistries.

A 13S lithium-ion battery typically requires 54.6V charging voltage, while a 16S LiFePO4 battery typically requires 58.4V.

The label “48V” or “51.2V” alone is not enough to select a charger.

Mistake 3: Ignoring Battery Chemistry

Li-ion and LiFePO4 are both lithium-based battery technologies, but their cell voltage characteristics differ.

Always verify chemistry before selecting a charger.

Mistake 4: Choosing Only by Connector

A connector can physically fit while the charger is electrically incompatible.

Connector size, polarity, voltage, current, and charging characteristics should all be confirmed.

For more information about connector selection, see How to Choose the Correct DC Plug Size.

Mistake 5: Assuming Higher Current Is Always Better

A charger with a higher current rating may not be appropriate for every battery.

The battery manufacturer’s recommended charging current should be followed.

Battery Charger Voltage Chart for Product Development

For OEM and product development projects, charger voltage selection should be considered during the early design stage.

A charger specification normally includes much more than output voltage.

Typical requirements include:

• Input voltage
• Output charging voltage
• Charging current
• Battery chemistry
• Battery capacity
• Charging profile
• DC connector
• DC cable length
• AC plug
• Charger form factor
• Operating temperature
• Protection requirements
• Certification requirements
• Quantity and target cost

For example, a project may require a:

58.8V 5A lithium-ion battery charger

This specification corresponds to approximately 294W output power.

At this power level, the charger design may require additional considerations such as thermal management, power factor correction, enclosure design, and applicable certification requirements.

For OEM projects, Guangdong QINX provides AC/DC battery charger solutions covering a range of charging voltages for lithium-ion, LiFePO4, lead-acid, and other battery applications.

Available charging-voltage categories include 12.6V, 14.6V, 16.8V, 21.0V, 25.2V, 29.4V, 36V, 42.0V, 54.6V, 58.8V, and other charging voltages depending on the project requirements.

For projects requiring a non-standard charging voltage, connector, cable, enclosure, or charging current, see Custom Battery Charger.

Standard and Custom Battery Charger Solutions

Not every battery-powered product can use an off-the-shelf charger.

A standard charger may be suitable when the battery specification, connector, charging current, cable, enclosure, input plug, and certification requirements already match an available model.

A custom charger may be more appropriate when the project requires:

• A specific charging voltage
• A specific charging current
• A special connector
• A longer or shorter cable
• A customized AC plug
• A different enclosure
• Specific mechanical dimensions
• Application-specific charging requirements
• OEM labeling or packaging
• Certification for a target market

For product manufacturers and distributors, working with the charger manufacturer during the design stage can help ensure that the electrical and mechanical requirements are considered together.

Guangdong QINX specializes in AC/DC adapters and battery chargers for B2B applications, with charger solutions covering different voltage, current, connector, cable, and form-factor requirements.

For a broader overview of charger selection, see How to Choose the Right Battery Charger.

Battery Charger Voltage Chart: Quick Reference

For quick reference, the most commonly encountered lithium battery charging voltages include:

These values are useful for initial specification and product research, but the battery manufacturer’s charging requirements should always take priority.

Frequently Asked Questions

Is a 12V battery charger actually 12V?

Not necessarily. “12V battery” usually refers to the battery’s nominal voltage. The required charger voltage depends on the battery chemistry and charging specification.

For example, a 3S lithium-ion battery has a nominal voltage around 11.1V and typically requires a 12.6V charger.

What charger voltage does a 12.8V LiFePO4 battery need?

A typical 4S 12.8V LiFePO4 battery uses a 14.6V charger.

However, always confirm the battery manufacturer’s specifications before charging.

What charger voltage does a 48V lithium battery need?

It depends on the battery configuration and chemistry. A common 13S lithium-ion battery uses a 54.6V charger, while a 16S LiFePO4 battery typically uses a 58.4V charger.

What charger voltage does a 36V lithium-ion battery need?

A common 10S lithium-ion battery has a nominal voltage around 36–37V and typically requires a 42V charger.

What charger voltage does a 21V lithium battery need?

A 5S lithium-ion battery has a nominal voltage around 18–18.5V and typically uses a 21V charger.

What charger voltage does a 24V LiFePO4 battery need?

A typical 8S LiFePO4 battery has a nominal voltage of 25.6V and uses approximately 29.2V as its full-charge voltage.

Therefore, a 29.2V charger is commonly used for this configuration.

Can I use a higher-voltage charger?

Do not use a charger with a higher output voltage unless it is specifically approved for the battery system.

The charging voltage must match the battery’s specified maximum charging voltage and charging method.

Does battery capacity change the charger voltage?

Battery capacity, normally expressed in Ah, primarily affects the required charging current and charging time. It does not normally determine the nominal voltage by itself.

For example, two 4S LiFePO4 batteries can both use a 14.6V charger even if one is 10Ah and the other is 40Ah. However, their recommended charging currents may be different.

Is charger voltage more important than charger current?

Both are important, but they perform different functions.

Voltage determines whether the charger is electrically compatible with the battery’s charging voltage. Current determines how much charging current the charger can deliver and influences charging time.

The correct charger must satisfy both requirements.

Final Takeaway

A battery charger’s output voltage should not be selected simply by matching the number printed on the battery label.

The correct selection starts with the battery chemistry and cell configuration.

For conventional lithium-ion batteries using a 4.2V-per-cell charging limit, common charging voltages include:

12.6V, 16.8V, 21.0V, 25.2V, 29.4V, 33.6V, 42.0V, 54.6V, and 58.8V.

For LiFePO4 batteries using a typical 3.65V-per-cell full-charge voltage, common charging voltages include:

14.6V, 29.2V, 43.8V, and 58.4V, depending on the series configuration.

For lead-acid batteries, charging voltage depends more strongly on battery type, charging stage, temperature, and manufacturer specifications.

The most important rule is simple:

Do not select a battery charger from nominal battery voltage alone.

Confirm the battery chemistry, series configuration, specified maximum charging voltage, charging current, and BMS requirements before choosing a charger.

For manufacturers developing battery-powered equipment, Guangdong QINX can support AC/DC battery charger requirements across different charging voltages, currents, connectors, cable configurations, and form factors.

For standard charger selection, explore AC/DC Battery Chargers.

For application-specific requirements, see Battery Charger for Lithium Battery Packs.