The Comprehensive Guide to Battery Voltage Charts
Understanding battery performance has always been a tough nut to crack. Since batteries are one of the most expensive components of any device, you must be familiar with how they work and how to help them last longer. This is where a battery voltage chart comes in handy.
A car battery voltage chart lets you learn how the battery voltage and its charge state are related to each other. With this chart, you can better understand how the battery components work and how to increase the overall lifespan by optimizing the performance.
Different battery types come with different voltage levels, and understanding them is crucial for perfect usage. This article presents battery voltage charts of different batteries to help you better understand the battery's performance and health.
What is battery voltage?
The battery voltage determines how much electrical power or electrical force a battery can provide to the circuit. Simply put, the electrical potential difference between the two terminals of the battery is known as its voltage.
Voltage plays a key role in determining the power output of a battery because it pushes electrons to flow through the conducting loop and enables them to turn on the attached load (motor, light bulb, or ceiling fan).
Higher battery voltages mean the battery can provide more power output. Monitoring the battery voltage is essential for its longevity and enhanced performance. The example below shows the relationship between the state of charge and battery voltage of a 12V battery.
| State of charge | Battery voltage (12V) |
| 100% | 12.7V |
| 90% | 12.5V |
| 80% | 12.42V |
| 70% | 12.32V |
| 60% | 12.20V |
| 50% | 12.06V |
| 40% | 11.90V |
| 30% | 11.79V |
| 20% | 11.58V |
| 10% | 11.31V |
| 0% (discharged) | 10.50V |
What is the state of charge and discharge?
The current energy level of a battery compared to its maximum capacity is known as the State of Charge (SoC) of that battery. SoC is represented in percentage. In simple words, you can call SoC a fuel gauge for batteries, as it tells you how much electrical charge is left behind before a battery needs recharging.
In contrast, if you want to know how much energy the battery has already used, the State of Discharge (SoD) will lend you a helping hand in this regard. Both SoC and SoD are important for monitoring a battery's performance and its health. A clear understanding of the state of charge and state of discharge helps you manage battery usage efficiently and increase its lifecycle.
Moreover, understanding SoC and SoD deeply enables you to prevent your batteries from over-discharging, which directly impacts the life cycle.
Battery voltage charts
As stated earlier, battery voltage charts can be used to track voltage. The primary goal of these charts is to extend the life cycle. This section presents voltage charts of different batteries to help you understand this subject more deeply.
1. LiFePO4 battery voltage chart
Lithium iron phosphate batteries have gained significant popularity and are starting to replace lithium-ion batteries because of their extended lifecycles, faster recharging, and added safety features. They offer a high depth of discharge and operate effectively in extreme temperatures. Therefore, LiFePO4 batteries are ideal for electric vehicles and home backup power systems like the Renogy LYCAN 5000 Power Box.
Moreover, lithium iron phosphate batteries are ethically sourced and more sustainable than conventional lithium-ion batteries. You can learn more about LiFePO4 vs Li-ion batteries in our guide. Below is a voltage chart of LiFePO4 batteries.
| Capacity | 12-volt battery | 24-volt battery | 48-volt battery |
| 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 |
2. AGM battery voltage chart
An AGM battery is known for its durability and efficiency. Though it is a subtype of lead-acid batteries, it needs minimal maintenance and performs efficiently in extreme temperatures. Below is a 12V, 24V, and 48V AGM battery voltage chart.
| Capacity | 12-volt battery | 24-volt battery | 48-volt battery |
| 100% (charging) | 13.0V | 26.0V | 52.0V |
| 100% (resting) | 12.85V | 25.85V | 51.70V |
| 99% | 12.80V | 25.75V | 51.45V |
| 90% | 12.75V | 25.55V | 51.10V |
| 80% | 12.50V | 25.00V | 50.0V |
| 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 | 47.64V |
| 10% | 11.51V | 23.02V | 46.04V |
| 0% | 10.50V | 21.00V | 42.0V |
3. Lithium-ion battery voltage chart
Li-ion batteries' lightweight structure, longer life cycle, and high energy density make them perfect for modern electronics. Below is the battery voltage chart of 1 cell, 12V, 24V, and 48V Li-ion batteries.
| Capacity | 1 cell | 12-volt battery | 24-volt battery | 48-volt battery |
| 100% | 3.40V | 13.6V | 27.2V | 54.4V |
| 90% | 3.35V | 13.4V | 26.8V | 53.6V |
| 80% | 3.32V | 13.3V | 26.6V | 53.1V |
| 70% | 3.30V | 13.2V | 26.4V | 52.8V |
| 60% | 3.27V | 13.1V | 26.1V | 52.3V |
| 50% | 3.26V | 13.0V | 26.0V | 52.2V |
| 40% | 3.25V | 13.0V | 26.0V | 52.0V |
| 30% | 3.22V | 12.9V | 25.8V | 51.5V |
| 20% | 3.20V | 12.8V | 25.6V | 51.2V |
| 10% | 3.00V | 12.0V | 24.0V | 48.0V |
| 0% | 2.50V | 10.0V | 20.0V | 40.0V |
4. Lead-acid battery voltage chart
It is the oldest battery that was a conventional choice for consumer electronics. Lead-acid batteries are commonly used in diesel-fueled and gasoline vehicles. Though it is affordable, it offers a shorter life cycle and lower energy density.
| Capacity | Flooded lead acid battery (6V) | Sealed lead acid battery (6V) |
| 100% | 6.32V | 6.44V |
| 90% | 6.26V | 6.39V |
| 80% | 6.20V | 6.33V |
| 70% | 6.15V | 6.26V |
| 60% | 6.09V | 6.20V |
| 50% | 6.03V | 6.11V |
| 40% | 5.98V | 6.05V |
| 30% | 5.94V | 5.98V |
| 20% | 5.88V | 5.90V |
| 10% | 5.82V | 5.85V |
| 0% | 5.79V | 5.81V |
Trusted off-grid solutions Renogy
Are you looking for a dependable off-grid solution to get a consistent and uninterruptible power supply? Renogy has a range of backup power solutions to meet your off-grid energy needs. A diverse collection of batteries at Renogy include core series deep cycle LiFePO4 batteries, cold weather LiFePO4 batteries, pro smart LiFePO4 batteries, solar batteries, AGM batteries, and more. Let's explore some unmatched off-grid solutions.
1. 12V 100Ah smart LiFePO4 battery
This ultra-safe lithium iron phosphate battery is a top choice for off-grid living. It comes with a built-in BMS, a 10-year lifespan, and up to 10.2kWh of expandable capacity. This battery enables you to monitor its status via Bluetooth. It can be a great choice if you are looking for a reliable battery to integrate with your solar system.
- Premium battery cells that last over 4000 cycles.
- A reliable BMS system with dual-processors.
- Works with the BT-2 Bluetooth module for real-time monitoring.
2. 24V 100Ah core series deep cycle LiFePO4 battery
Using this battery with your solar electric system will be worth it if you live in an off-grid environment in extreme temperatures. It offers self-heating functionality and 80% depth of discharge for reliability. Moreover, low-temperature cut-off ensures safe charging and discharging.
- Industry-leading 200W self-heating for peak cold-weather performance.
- Grade A EV-class cells with 5000 cycles at 80% DOD for reliability.
3. 48V 50Ah smart LiFePO4 battery
This battery heats up automatically for safe charging. It lasts up to 6,000 charge cycles. If you use a suitable charge controller and your solar panel output matches the battery voltage, you can use this battery as a reliable backup power source with your solar system.
- Impressive 6000 Cycle Life.
- Automatically heats up for safer charging below 32°F.
- Expandable capacity for 19.2kWh of backup power(8P).
Battery voltage chart faqs
What voltage is considered a bad battery?
A 12V car battery is considered bad if its voltage drops to 12.2V or lower when the engine is not running. A fully-charged car battery should maintain around 12.6V. If the voltage of your car battery is between 12.4V and 12.8, it will be considered in good condition. If it is between 12.1 and 12.4, the battery is partially discharged. Anything below 12.1 means that the battery is fully discharged and needs recharging.
What voltage is a 12V battery at 50%?
When a 12V battery voltage drops to 12.05V, it reaches its 50% capacity. At 100% capacity, the voltage should be around 12.70 volts.
At what voltage should a battery be replaced?
If you measure the battery voltage when it is at rest (or when the engine is off) and find it to be somewhere below 12.4 volts, you should replace the battery. For a 24V battery, if the open-circuit voltage is below 24.5V, it is time for the replacement.
Final words
Understanding the battery voltage is important, as it determines the overall performance, lifespan, and safety of the battery. The state of charge and state of discharge plays a key role in monitoring the battery's energy level compared to its maximum capacity. Battery voltage charts are essential to understanding the relationship between the battery's charge state and voltage.
If you need a reliable and long-lasting backup power solution for off-grid living, Renogy offers various options to fulfill your energy needs in areas where there is no grid supply. You can find a range of batteries to couple with your home solar systems and other energy sources for maximized performance and enhanced efficiency.
