Essential information for end of life vehicle dismantling, depollution and recycling

May 11, 2026

Greater battery health variation among used PHEVs than BEVs, Generational analysis shows

Used PHEVs show broadly strong average battery health, but greater variation than BEVs, Generational’s analysis finds. For retailers, remarketers and buyers, the key issue is not widespread degradation but uncertainty: similar-age plug-in vehicles can have very different battery histories, making transparent State of Health testing vital for pricing, risk and confidence.

Analysis of 2,000 used plug-in hybrid and battery-electric vehicles from automotive retailers finds PHEVs have a wider spread of battery State of Health, despite broadly similar average battery performance.

Data underscores the importance of battery transparency in used plug-in market.

Generational, the UK-based innovator in electric vehicle battery condition diagnostics, has today published new analysis comparing battery performance across used plug-in hybrid electric vehicles (PHEVs) and battery-electric vehicles (BEVs) from automotive retailers across the country.

The analysis, covering 1,000 PHEVs and 1,000 BEVs of comparable age and mileage, found that both vehicle sets retained strong average battery State of Health (SoH). However, Generational observed materially greater variation among PHEVs, suggesting that PHEV battery performance may be more heavily shaped by differing usage profiles, charging behaviour and driving patterns than those seen in BEVs.

Across the PHEV cohort, average SoH stood at 94.27%, with a standard deviation of 5.48%. By comparison, the BEV cohort recorded a slightly higher average SoH of 94.94%, with a lower standard deviation of 4.14%.

Generational also found that 4.70% of PHEVs in the sample had an SoH below 85%, compared with 1.50% of BEVs. While the proportion of lower-performing vehicles remains small across both groups, PHEVs were more than twice as likely to fall below that threshold within this dataset.

The findings point to a notable difference in how PHEVs and BEVs are used in the real world. BEVs are generally dependent on the battery as the vehicle’s primary energy source, meaning owners and operators typically develop more consistent charging and usage routines.

PHEVs, by contrast, can be used in a wider range of ways; some are charged frequently and driven largely on electric power, while others may rely more heavily on the combustion engine, or may experience shallower, more frequent charge and discharge cycles.

As a result, two PHEVs of similar age and mileage may have very different battery histories. This makes verified battery testing an essential part of the decision-making process for retailers, remarketers, financiers and buyers seeking to understand the true condition of a used plug-in vehicle.

Oliver Phillpott, CEO of Generational, said:

“Average state of health evidently remains strong across both PHEVs and BEVs. What stands out is the wider spread of results among PHEVs, which underscores how both buyer and seller need to double down on checking the usage profile of the vehicle in question.

Even while the averages are reassuring, for both parties the data reinforces how battery condition is something that needs to be assessed on a case-by-case basis. Transparent testing allows strong vehicles to be priced confidently and problematic vehicles to be identified early. So, across both segments, retailers and consumers can go into the market confident of finding a robust vehicle to meet their needs.”

The new PHEV-versus-BEV analysis follows the publication of Generational’s 2025 Battery Performance Index. Based on more than 8,000 battery health assessments conducted in 2025, the Index found average battery health of 95.15% across tested vehicles, with even 8-9-year-old vehicles retaining around 85% median capacity, comfortably above common OEM warranty thresholds. It also found that high-mileage EVs with 100,000+ miles frequently returned 88-95% SoH, challenging the assumption that mileage alone is a reliable predictor of battery condition.

The Battery Performance Index concluded that battery degradation is not the systemic risk it is often assumed to be, but that variance between individual vehicles becomes more important as vehicles age. It also argued that uncertainty, rather than underlying battery longevity, is now one of the principal constraints on used EV confidence, residual values and transaction efficiency.

Phillpott added:

“The used EV and PHEV market is entering a rapid growth phase. Buyers increasingly understand that the battery is the most valuable component in the vehicle, but they still need clear, trusted information before they can buy with confidence.

Our latest analysis shows why a single mileage or age figure cannot tell the whole story. Battery condition is becoming the defining factor in used plug-in vehicle value, and the industry now has the data and tools to make that condition visible.”

Generational’s battery health checks and State of Health certification are designed to help retailers, leasing companies and remarketers assess used EV batteries quickly and consistently. The company says its tools enable retailers to certify battery health and real-world range, support stronger buyer confidence and reduce risk when acquiring, valuing and selling used plug-in vehicles.