How to Test an Electric Car Battery

Electric cars are powered by Lithium-ion rechargeable batteries that have proven to produce high energy density compared to the traditional nickel-cadmium or lead-acid batteries. However, these batteries lose their efficiency as they get older, which directly relates to their performance. That’s why it’s better to know how to test your electric car battery to determine the remaining lifespan and prepare for a replacement if it’s needed.

Electric car batteries are tested based on their performance. Test the amount of time they take to fully charge, how long they can run on a full charge, and if they’re able to power all electronics in the car. However, you should also check how long you’ve used the battery since many have a minimum lifespan of 10 years.

That’s not all, as you still need to know how long an electric car battery can last and the signs of a failing electric car battery, which you will learn if you read on.

How Can You Test An Electric Car Battery From Home?

A fully charged electric car battery should be able to power a vehicle under different circumstances. However, the battery’s performance tends to slope downwards after prolonged use, which might be hard to notice in the early years. Still, you can determine the battery’s remaining lifespan with simple testing.

The tests are straightforward, and they mostly require observing and taking into account critical details, which can be done from the comfort of your home. You also don’t necessarily need fancy gadgets since you’ll be relying on your data collection skills.

Here’s how you can test an electric car battery to know if it’s still as efficient as before:

Study the Time It Takes the Battery to Charge

Depending on the size of the car, an electric car’s battery should take anywhere between 10 and 24 hours to fully charge. However, the charging time tends to vary as the battery ages, with some experiencing a longer charge time while others take a shorter time. Even so, the difference in charging time is hardly noticeable in the first few years, but it often becomes clear that the electric car battery is losing its efficiency when it enters its sixth year in service.

If by any chance the battery is taking shorter or longer periods to charge, it signifies that it’s approaching its end, and a replacement might be needed.

Note How Far You Can Drive on a Fully Charged Battery

The type of car you have will determine how far you can drive on a fully charged electric battery. As a rule of thumb, the more power the battery can hold, the further it can power the car. A majority of cars are known to clock an average of 200 miles without recharging.

If, by any chance, you notice your car is unable to hit the 200 miles consecutively, even on a fully charged battery, it’s time you start budgeting for a replacement. However, you shouldn’t rush to replace the battery yet without investigating further, as several other things can drain power from electric car batteries fast. They include:

  • Driving too fast – The vehicle will require more power supply to accommodate high-speed driving, which ends up draining power from the batteries faster.
  • The condition of the roads – Driving off-road requires more power than driving on a highway.
  • The size of the vehicle – Big vehicles require a lot of horsepower to drive fast, which in return drains power from the battery very fast.  

Observe The Battery’s Ability to Power Electronics in the Car

Electric cars have simpler structures compared to traditional cars, and they’re made up of interconnected electrical components. All these components require a power supply to function, which may draw power from the battery too quickly.

Powering these electrical components is not a concern for a new electric car battery since it can store more power that can be distributed through the vehicle. However, the task to supply such an enormous amount of power to the vehicle becomes overwhelming to the battery as it ages. Take note if using too many devices at once causes a noticeable effect on mobility.

Use an Electric Vehicle Battery Degradation Tool

Mechanics use tools such as Geotab to determine the degradation levels in the electric vehicle’s battery that occurs over time. The tool collects critical data that highlights the battery’s State of Health (SOH). The data then shows the rate at which the battery loses its efficiency, and which parts of the cells are affected the most.

It’s one of the best ways of testing the battery’s lifespan and the overall state of health since the data is extremely reliable and accurate. The data is presented in graph form, with critical details highlighted next to the diagram.

Unless you understand how to interpret the data, this tool may not be of much use to you, not to mention the cost associated with purchasing one. Nonetheless, it sheds light on how you’re using the battery more accurately compared to other methods we’ve mentioned above.

What Is The Lifespan Of An Electric Car Battery?

On average, an electric car battery is expected to last a minimum of eight years or 100,000 miles. However, there are cases where these batteries have been known to last up to 10 years. The battery can also cover at least 200 miles before recharging.

The battery’s lifespan is also affected by factors such as:

  • Hot climates – Electric car batteries are known to degrade fast in hot climatic areas compared to cold ones. A combination of the scorching sun and the heat from the battery when being used ends up taking a toll on the battery’s lifespan.
  • Using fast charging too often – Fast charging is effective since you can be up and running within 45 minutes. However, relying on this charging method more often will drain the life out of the battery.
  • Overcharging – Plugging your car overnight might lead to overcharging, which ends up damaging the cells and ultimately affecting the battery’s lifespan.

What Are The Signs Of A Failing Electric Car Battery?

An electric car battery is supposed to last a minimum of six years for frequent travelers before it starts to fail. During this time, the battery gives off signs such as dimmed headlights to indicate it’s coming towards the end of its lifespan.

If your electric car battery starts giving off one or more of these signs, then it’s time for you to start shopping for a replacement:

  • You have to step on the gas to start – You shouldn’t have to press down on the gas pedal to get your car started.
  • Dim headlights – A failing battery is incapable of powering electrical components, and that includes the headlights.


You can put the electric car battery through a series of tests to determine its remaining lifespan and how it’s degrading. You can tell a lot about whether the battery is degrading fast by checking how long it takes to charge, how far you can drive on a charged battery, and how well it powers the electrical components in the car. Electric vehicle battery degradation tools are also handy, especially to mechanics, as they provide accurate data.

The batteries have an average lifespan of eight years, and you can also drive at least 200 miles on a fully charged battery. Hot temperatures, fast charging, and overcharging can affect the overall lifespan of the battery. Dim headlights and a need to step on a gas every time you start a car are signs of a failing battery.

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