Reference Guide of Battery Voltage

Battery voltage charts are important tools for understanding the relationship between a battery’s state of charge and its voltage. In solar systems, battery selection plays a major role in overall performance, lifespan, and efficiency. This article will guide you through different types of battery voltage charts, focusing primarily on lead-acid and lithium-ion batteries. By the end, you’ll have a solid understanding of each battery type and which may be best suited for your solar setup.

Catalog

Different Lead-Acid Battery Voltage Chart

Lead-acid batteries are among the oldest and most widely used batteries, often found in off-grid solar systems. There are two primary types: flooded lead-acid (FLA) batteries, also known as wet cells, and absorbent glass mat (AGM) lead-acid batteries. Each has distinct characteristics that affect maintenance requirements, cost, and performance.

Flooded Lead-Acid (FLA) Battery Voltage Chart

FLA batteries are the more economical choice but require regular maintenance, including checking water levels and performing equalization charges. They release hydrogen gas when charging, so proper ventilation is necessary to avoid buildup of fumes. Despite their lower upfront cost, FLA batteries tend to wear out faster than their AGM counterparts, especially if not properly maintained.

Understanding the voltage characteristics of a 6V flooded lead-acid battery is crucial for ensuring optimal performance and longevity. This voltage chart provides good information about the battery's state of charge, discharge levels, and overall health. By referring to this chart, you can accurately monitor their battery’s performance, make informed decisions regarding maintenance, and enhance the efficiency of their applications. Whether you're using these batteries for renewable energy systems, golf carts, or other equipment, this guide will help you interpret the voltage readings effectively.

Voltage	Capacity
6.32V	100%
6.26V	90%
6.20V	80%
6.15V	70%
6.09V	60%
6.03V	50%
5.98V	40%
5.94V	30%
5.88V	20%
5.82V	10%
5.79V	0%

AGM Lead-Acid Battery Voltage Chart

AGM batteries are a more advanced version of lead-acid batteries, as they are sealed and require less maintenance. The electrolyte in AGM batteries is absorbed into fiberglass mats, reducing the risk of spills and eliminating the need for ventilation. They typically offer longer charge cycles and are more durable, making them a popular choice for solar systems that need reliable performance with minimal upkeep.

Voltage	Capacity
6.44V	100%
6.39V	90%
6.33V	80%
6.26V	70%
6.20V	60%
6.11V	50%
6.05V	40%
5.98V	30%
5.90V	20%
5.82V	10%
5.79V	0%

12V Lead-Acid Battery Voltage Chart

In solar systems, 12V lead-acid batteries are popular for their affordability and reliability. The two main types are AGM (sealed) and Flooded (FLA) batteries, each with unique voltage characteristics that affect their performance and maintenance needs. AGM batteries require minimal maintenance, as they are sealed and don’t need watering or ventilation. They are well-suited for enclosed spaces and have a slightly higher full-charge voltage than flooded batteries.

• Full Charge Voltage: ~12.89V
• Fully Discharged Voltage: ~12.23V
• Optimal Use Range: 50% to 100% (12.23V - 12.89V)

Voltage	Capacity
12.89V	100%
12.78V	90%
12.65V	80%
12.51V	70%
12.41V	60%
12.23V	50%
12.11V	40%
11.96V	30%
11.81V	20%
11.70V	10%
11.63V	0%

Flooded batteries are cheaper but require regular maintenance, including refilling with distilled water and ensuring proper ventilation. They have a slightly lower full-charge voltage compared to AGM batteries.

• Full Charge Voltage: ~12.64V
• Fully Discharged Voltage: ~12.07V

Voltage	Capacity
12.64V	100%
12.53V	90%
12.41V	80%
12.29V	70%
12.18V	60%
12.07V	50%
11.97V	40%
11.87V	30%
11.76V	20%
11.63V	10%
11.59V	0%

Using these voltage charts helps you monitor and maintain your lead-acid batteries, maximizing their lifespan and performance in your solar setup.

Types of Lithium-Ion Battery Voltage Chart

Lithium-ion batteries, particularly lithium iron phosphate (LiFePO4) batteries, are becoming increasingly popular for solar systems due to their long lifespan, low maintenance, and high safety standards. Unlike lead-acid batteries, they do not require full charges and can function effectively across a wide range of charge states. They are also less prone to voltage fluctuations and can be stored without ventilation. Lithium batteries come with built-in battery management systems (BMS) that protect them from overheating, overcharging, and deep discharges, adding an extra layer of safety.

12V Lithium-Ion Battery Voltage Chart

The 12V lithium-ion battery voltage chart is an important tool for monitoring the battery's state of charge and performance. This chart helps you understand voltage levels during charging and discharging, enabling better maintenance and longevity of the battery. Whether used in electric vehicles, portable electronics, or renewable energy systems, accurate voltage tracking is key to optimizing battery efficiency and safety

Voltage	Capacity
14.6V	100% (charging)
13.6V	100% (resting)
13.4V	99%
13.3V	90%
13.2V	70%
13.1V	40%
13.0V	30%
12.9V	20%
12.8V	17%
12.5V	14%
12.0V	9%
10.0V	0%

48V Lithium-Ion Battery Voltage Chart

The 48V lithium-ion battery voltage chart serves as an important reference for understanding the battery's charge and discharge characteristics. This chart allows you to easily monitor voltage levels, ensuring good performance and extending the battery's lifespan. Commonly used in electric vehicles, solar energy systems, and various high-power applications, this voltage chart is for effective battery management and maintenance, promoting safety and efficiency in operations

For larger solar systems, a 48V lithium-ion battery setup may be more appropriate. Here’s a quick look at the voltage levels associated with a 48V lithium-ion battery.

Voltage	Capacity
57.6V	100% (charging)
54.4V	100% (resting)
53.6V	99%
53.2V	90%
52.8V	70%
52.4V	40%
52.0V	30%
51.6V	20%
51.2V	17%
50.0V	14%
48.0V	9%
40.9V	0%

Charging Voltage Guide of Battery

The voltage of a battery can provide a good indication of its charge state. For lead-acid batteries, specific gravity readings with a hydrometer can give a more precise measure of charge. For lithium-ion batteries, voltage readings tend to be more stable, making them easier to monitor with just a voltmeter.

Percentage of Charge	12V Battery Voltage	Specific Gravity (Lead-Acid)
100%	12.70V	1.265
95%	12.64V	1.257
90%	12.58V	1.249
80%	12.46V	1.233
50%	12.20V	1.190
0%	11.90V	1.120

Discharge Capacity Chart of Battery

Battery discharge rates vary based on the load applied to the battery. Larger batteries with higher amp-hour (Ah) ratings can support higher discharge currents without voltage drop. The following table provides maximum discharge rates for various battery capacities.

Battery Capacity (Ah)	7-Minute Max Discharge Current	30-Minute Max Discharge Current
5Ah	15 Amps	10 Amps
10Ah	31 Amps	21 Amps
22Ah	66 Amps	46 Amps
35Ah	105 Amps	84 Amps

Conclusion

Choosing the right battery for a solar system involves understanding the voltage characteristics of each battery type and how they align with your needs. Lead-acid batteries are affordable but require maintenance, whereas lithium-ion batteries offer durability and low upkeep, albeit at a higher initial cost. By using battery voltage charts, you can monitor and optimize your battery’s performance, ensuring your solar system runs efficiently for years to come.