Specifications Of An Electric Vehicle Battery

Over the past few decades, the cost of living has continued to increase dramatically. Unfortunately, the cost is directly opposite of what is taking place on people’s income. The salaries have remained constant or grown with a slight margin. As a result, most individuals, if not all, are left struggling to make ends meet.

A notable number of people are forced to work more than two shifts a day, to meet their daily needs. When it comes to expenses, people have come up with plans aimed at reducing their daily expenses at all cost.

Today, an electric vehicle is still and will remain a perfect choice for every individual out there seeking to save on expenses. Because of the recent fuel prices, a typical driver is likely to spend roughly $400 of their monthly income on fuel.

Owning an EV is, therefore, a great move as it can see all this money put into better use. When it comes to an electric vehicle, the battery remains the most crucial and expensive component.

For instance, replacing an electric car’s battery can cost you up to $6000 of your hard-earned money. The figure is quite a big investment. Therefore, when it comes to shopping for the car’s battery, one has to be extra cautious to avoid complications. Like many other fields, you’re likely to encounter plenty of electric vehicle battery specifications when shopping for the ideal option.

If not careful with the specifications and terminologies, you’re likely to lose your money by buying the wrong item. Without saying much, here are some basic battery specifications that you should know.

Guide to 21 Electric Car Battery Specifications

1. Cells, Modules, and Packs

Every EV or hybrid vehicle has a battery that is known to be of high voltage. The battery comprises of modules and cells which are often organized in either parallel or series. A cell is usually the smallest and packaged form that the battery can take.

A module on the other end is a group of cells joined together in either parallel or series form. The modules are then joined together to form what we term a battery pack. These modules are also joined in either series or parallel.

2. Classifications

Batteries are classed into various categories. Different battery brands offer unique energy and power. For instance, a battery can be classed as either high-energy or high-power and not both. It’s upon you to know your suitable class of battery.

Manufacturers use these classifications to differentiate their products. Also, you may bump into a battery labeled high durability. Well, the labeling simply means that the battery has been enhanced to improve its life at the expense of its energy and power.

3. Secondary/Primary Cells

It may sound like obvious, but you’ve to understand that there is a difference between a primary cell and a secondary one. The batteries you will find in all-electric, hybrid, and plug-in cars, for example, are secondary. This, therefore, means that the cells can be recharged whenever they run out. On the other end, a primary cell can’t be recharged when out of charge.

4. C and E Rates

When shopping for a battery replacement, you’re likely to encounter C and E rate. The C-rate in this scenario is used to describe the battery’s discharge current. The rate simply describes the rate at which your preferred battery discharges with its optimum capacity.

Say, for instance, a 1C rated battery will drain all its energy within an hour. On the other end, an E-rate is used to describe the discharge power. For example, a 1E rate states the power needed to drain the entire battery within a given hour.

5. Tate of Condition (SOC)

Often expressed in percentages, the state of condition is used to tell the battery’s present capacity. This expression is usually derived using the current integration. The battery’s state of condition is vital because it helps determine the amount of charge present in the battery within a specific time.

6. Terminal Voltage (V)

Terminal voltage can simply be defined as the voltage between terminals with a load applied. It varies with discharge/charge current and the battery’s state of condition.

7. Depth of Discharge (DOD)

The depth of discharge is also expressed in the form of percentages. The DOD is usually derived by finding the percentage of a discharged battery against the percentage of maximum capacity. When a battery is discharged to about 80%, we can say that it’s on deep discharge.

8. Open-circuit voltage (v)

As the name suggests, open-circuit voltage implies the voltage between the battery terminals with no load in place. This voltage is dependent on the battery’s state of charge. This, therefore, means that the open-circuit voltage is likely to increase with your battery’s state of charge and vice versa.

9. Internal Resistance (IR)

Internal resistance is used to depict the resistance within the battery. When choosing a battery for your EV, it’s advisable to go with one that has a lower IR. Higher internal resistance means reduced performance. Also, a high internal resistance means reduced thermal stability because much of the battery’s energy is usually converted into heat energy.

10. Nominal Voltage (V)

You’re likely to bump into this term on the battery’s technical specifications sheet. The nominal voltage is the reference or reported voltage for a given battery.

11. Nominal energy

The nominal energy is simply the energy capacity of a battery. In other words, it’s the total Watt-hours available when that particular battery is drained at a specific discharge current from 100% charge to the cut-off voltage.

To find the battery’s nominal energy, you multiply the battery’s discharge power by the discharge time. The battery’s nominal energy decreases with an increase in the discharge current and vice versa.

12. Cut-off Voltage

The cut-off voltage is also another specification that you’re likely to find on the battery’s specifications. It’s usually the minimum amount of voltage allowed in a given battery. The cut-off voltage is what defines the battery’s empty state.

13. Charge Voltage

As the name suggests, charge voltage is amount of voltage in which your battery is charged when filled to full-charge.

14. Float Voltage

After filling the battery to full capacity, you need to maintain that state of condition. The voltage you need to maintain that state is what we call a float voltage. Float energy helps maintain the optimum charge by compensating for self-discharging.

15. Recommended Charge Current

The recommended charge current is usually the standard current in which the battery is first charged under sturdy charging scheme before proceeding into constant voltage charging.

16. Cycle Life

The cycle life is one thing that you must put into consideration when choosing the right battery for your EV. Cycle life is the actual quantity of discharge-charge cycles that a battery can withstand before it fails to deliver or, in other words, die.

The battery’s cycle life is affected by several factors among them temperature, humidity and depth and rate of cycles. Therefore, a battery with a higher DOD is likely to have a short cycle life.

17. Specific Energy (Wh/kg)

This is the energy per unit mass of a nominal battery. You’re likely to bump into the term specific energy on your battery’s specifications manual. Your battery’s specific energy, together with the EV’s energy usage can be used to tell the battery’s weight needed to give a specific power.

18. Specific Power (W/kg)

It’s also a common term on a battery’s specification’s packaging. It dictates the optimum power present with the battery’s unit mass in the picture. This unit determines the battery weight needed to attain a given performance target.

19. Maximum Continuous Discharge Current

As its name implies, this term usually determines the maximum current through which your car’s battery can be drained continuously. The figure is usually written by the battery’s manufacturers on its specifications. Failure to observe the maximum continuous discharge current can lead to excessive discharge rates.

In return, the excessive discharge can damage the car’s battery, as well as reduce its holding capacity. In conjunction with the maximum continuous power of the motor, this figure can be used to dictate the vehicle’s acceleration.

20. Energy Density (Wh/L)

Often termed to as the volumetric energy, the energy density can be defined as the nominal battery energy over unit volume. The energy density remains an important term, and that you must observe when going through the battery’s specifications.

The battery’s energy density is vital as it can be used (together with your car’s energy usage) to determine the size of the battery required to provide a certain amount of electric power.

21. Power Density (W/L)

The battery’s power density defines the maximum available power per unit volume. The figure dictates the size of a battery needed to achieve a specific performance target.


Shopping for an electric vehicle battery is an easy task. However, that’s not the case with all the buyers out there. Well, with all the terminologies and battery specifications, the job can be overwhelming.

Explained in this article are some of the basic specs you’re likely to encounter when acquiring a battery for your EV. Read through each one of the specifications to understand the world of your EV’s battery well. Understanding these specifications will not only make your shopping easy but will also ensure that you pay for the right battery for your car.