Battery SOH: How to Know if a Used Electric Car Is Worth Buying (and Check It in 1 Minute)

Battery SOH: The hidden number that determines a used EV's real value

The used electric vehicle market is growing rapidly around the world.

As more EVs reach the end of their first ownership cycle, buyers are gaining access to increasingly affordable electric cars. For many consumers, purchasing a used EV can provide substantial savings while still delivering the benefits of electric mobility.

However, there is one critical factor that many buyers overlook.

Battery health.

More specifically, Battery SOH, or State of Health.

While traditional used car buyers typically focus on mileage, service history, and cosmetic condition, EV buyers need to pay close attention to the battery. After all, the battery is the most valuable component in any electric vehicle.

A healthy battery can provide years of reliable service and strong resale value.

A degraded battery can significantly reduce range, impact driving experience, and affect long-term ownership costs.

That's why understanding Battery SOH has become one of the most important skills for anyone considering a used electric vehicle.

What is Battery SOH?

SOH stands for State of Health.

It measures the current usable capacity of a battery compared to its original factory capacity when new.

A brand-new battery typically starts at 100% SOH.

Over time, all lithium-ion batteries experience some level of degradation due to chemical aging and repeated charging and discharging cycles.

For example:

• 100% SOH means the battery retains its original capacity.
• 95% SOH means approximately 95% of original capacity remains.
• 90% SOH means the battery has lost around 10% of its original capacity.

This metric provides a simple way to understand how much performance the battery still has available.

For EV buyers, it serves as one of the clearest indicators of the vehicle's long-term value.

Why Battery SOH matters more than mileage

For decades, mileage has been the primary metric used to evaluate used vehicles.

Electric vehicles change that equation.

Two EVs with identical mileage can have dramatically different battery conditions.

Consider the following example:

Vehicle A:

• 60,000 miles
• 96% SOH

Vehicle B:

• 60,000 miles
• 84% SOH

Both cars have traveled the same distance.

Yet Vehicle A may offer significantly more usable range and better long-term value.

Battery health depends on many factors beyond mileage, including:

• Charging habits
• Climate conditions
• Fast charging frequency
• Time spent at high states of charge
• Thermal management systems
• Battery chemistry

This means mileage alone cannot accurately tell you how healthy an EV battery really is.

The biggest mistake used EV buyers make

Most buyers spend hours comparing:

• Vehicle prices
• Exterior condition
• Features and options
• Service history

Yet many never ask about battery health.

This is surprising because the battery is often the most expensive component in the entire vehicle.

Depending on the model, battery replacement costs can range from several thousand dollars to tens of thousands of dollars.

Buying an EV without checking battery health is similar to buying a house without inspecting its foundation.

Everything may look good on the surface, but hidden issues can dramatically affect value.

How Battery SOH affects real-world range

One of the most direct consequences of battery degradation is reduced driving range.

Imagine a vehicle with an original EPA range of 300 miles.

At 100% SOH:

• Approximately 300 miles available

At 90% SOH:

• Approximately 270 miles available

At 80% SOH:

• Approximately 240 miles available

While real-world driving conditions also influence range, Battery SOH provides a strong baseline for estimating what the vehicle can realistically deliver.

This is especially important for buyers who regularly drive long distances or rely on public charging infrastructure.

What is considered a good Battery SOH?

There is no universal answer because battery health must always be considered alongside age, mileage, and vehicle type.

However, these general guidelines can help.

Above 95%

Excellent condition.

The battery remains very close to factory performance.

Between 90% and 95%

Very good condition.

Most drivers will notice little to no difference in daily use.

Between 85% and 90%

Good condition.

Still suitable for most buyers and driving scenarios.

Between 80% and 85%

Requires closer evaluation.

The price should reflect the reduced battery capacity.

Below 80%

Proceed carefully.

Depending on the manufacturer, this may approach warranty thresholds or indicate significant degradation.

Battery degradation is often less severe than people think

One of the biggest misconceptions about electric vehicles is that batteries quickly become unusable.

Real-world data tells a different story.

Studies analyzing thousands of electric vehicles show that modern EV batteries often retain the majority of their capacity even after many years of use.

Advances in:

• Battery chemistry
• Thermal management
• Charging algorithms
• Vehicle software

have dramatically improved battery longevity.

For many owners, battery degradation occurs gradually and predictably rather than suddenly.

The challenge is not that degradation exists.

The challenge is knowing exactly how much degradation has occurred in a specific vehicle.

The transparency problem in the used EV market

Unlike mileage, Battery SOH is rarely displayed in used car listings.

Many sellers simply don't provide battery health information.

As a result, buyers often make purchasing decisions without understanding the condition of the vehicle's most valuable component.

This creates uncertainty.

It also creates opportunities for both overpaying and undervaluing vehicles.

A transparent battery evaluation helps eliminate this uncertainty.

How to evaluate an EV battery in 1 minute

Thanks to modern tools, battery evaluation no longer requires specialized equipment or technical expertise.

The SuperCarros24 Battery Evaluation platform allows users to quickly estimate battery health and gain valuable insights before making a purchase decision.

Using the tool is simple:

1. Enter the required vehicle information.
2. Receive a battery health estimate.
3. Review the potential impact on range.
4. Compare results against expected values.

Official Battery Evaluation Tool:

https://www.supercarros24.pt/ev-battery-health

The entire process takes approximately one minute and can provide information that may save thousands in future ownership costs.

Why battery evaluation changes the buying process

Battery evaluation transforms used EV purchasing from guesswork into data-driven decision making.

Instead of relying solely on:

• Seller claims
• Vehicle appearance
• Mileage

buyers can make decisions based on measurable battery health.

This creates several advantages:

• Better price negotiations
• More accurate vehicle comparisons
• Reduced financial risk
• Greater confidence in the purchase

For many buyers, battery evaluation becomes one of the most valuable steps in the entire purchasing process.

Why Battery SOH is becoming the new mileage

The automotive market is evolving.

As electric vehicles become mainstream, battery health is increasingly viewed as a core vehicle metric.

Industry experts expect Battery SOH to become as common in listings as:

• Mileage
• Vehicle age
• Service history

Some markets are already moving toward battery certification and independent battery reports.

This shift benefits both buyers and sellers by creating greater transparency and trust.

Conclusion

Buying a used electric vehicle can be one of the smartest automotive decisions you make.

But unlike traditional vehicles, understanding battery health is essential.

Battery SOH provides insight into the vehicle's remaining capacity, expected range, long-term value, and overall condition.

It helps buyers avoid costly surprises and make more informed purchasing decisions.

Most importantly, evaluating battery health no longer requires specialized knowledge or expensive diagnostics.

With the SuperCarros24 Battery Evaluation tool, anyone can gain valuable battery insights in about a minute.

In today's used EV market, the difference between a great deal and an expensive mistake often comes down to a single number:

Battery SOH.