One of the biggest unknowns in the used electric vehicle (EV) market is about to be addressed. Manheim Australia has announced the introduction of independent battery health testing for all EVs sold at auction, through a strategic partnership with European diagnostics leader, Aviloo.
From September 2025, sellers consigning EVs to Manheim auctions in Melbourne, Sydney and Brisbane can now opt for a certified battery State of Health (SoH) report to be included in the listing. A phased rollout across the rest of Australia and into New Zealand will follow soon after.
This is a major development for the fleet sector, where EV residual values, remarketing strategies and whole-of-life costs are top of mind.
Why Battery Health Matters
For internal combustion engine (ICE) vehicles, resale buyers usually focus on mileage, service history and cosmetic condition. For EVs, the single most important factor is the health of the lithium-ion battery pack, which accounts for up to half of the vehicle’s total value.
Mike Costello, Corporate Affairs Manager and Analyst at Manheim Australia, said the new service is designed to directly address this issue:
“The research we see shows that a key concern for prospective used EV buyers – both dealers and the public – is the health of the battery, both for the now and for the future. Auction buyers will come to expect independent battery health assessments attached to EVs they are looking to bid on, so we see the Aviloo Battery Certification as key to our wider EV strategy.”
Without an objective assessment, buyers tend to assume the worst, which pushes down residual values and lengthens selling times. The Aviloo SoH test provides a verified percentage score for remaining battery health, along with an estimated WLTP range compared to new.
How the Test Works
The Aviloo “Flash Test” is simple and non-intrusive. A small device, about the size of a TV remote, plugs into the EV’s OBD port and collects diagnostic data from the vehicle’s systems. The results are analysed by Aviloo, which then issues a certificate as a PDF.
The certificate provides:
- A topline State of Health percentage.
- An estimated WLTP driving range compared to when the vehicle was new.
- A time-stamped record that can be used at auction and later when the vehicle is retailed.
For vendors, the certificate appears on the auction listing as a clickable button and image in the carousel, ensuring maximum visibility to buyers. Dealers who purchase the vehicle can then pass on the certificate to their retail customers.
Impact on Residual Values
Emerging data from Europe shows the clear commercial benefits of including a battery health certificate. Manheim Express in Germany collated 12 months of auction results on EVs with and without Aviloo SoH tests. The findings were striking:
- EVs with a certificate achieved a 15% higher clearance rate.
- They also attracted 22% more bids than uncertified EVs.
At the retail level, Aviloo’s consumer research reinforces the story. Buyers said they were willing to pay between $1,000 and $2,000 more for an EV with a health certificate, and 81% considered dealers offering such certificates to be more trustworthy.
For Fleet Managers and Finance Managers, this could help close the residual value gap that has been a sticking point in EV whole-of-life cost (WOLC) models.
EV Remarketing Challenges
While EVs still represent a small share of vehicles sold at Manheim auctions, the numbers are climbing fast. Sales volumes in H1 2025 were more than three times higher than the previous year. With more de-fleeted EVs entering the market, remarketing strategies will become critical.
For many organisations, the business case for EVs has been undermined by conservative assumptions on residual values. Fleets are already seeing lower fuel costs from EV adoption, but higher upfront purchase prices and uncertain resale values have limited whole-of-life savings.
By providing transparency and reducing risk for buyers, battery testing could be the missing link to stabilise and improve resale prices. This not only supports Fleet Managers’ procurement decisions but also strengthens the business case presented to Finance Managers and executives.
A Global Perspective
Austria-based Aviloo is the world leader in EV battery diagnostics, with over 2,000 clients across Europe, Asia, the US and Australia. It is one of only three providers certified by the Car Remarketing Association Europe (CARA), and its testing ecosystem covers 95% of EV and PHEV models, including most new Chinese vehicles entering the Australian market.
Dr Marcus Berger, CEO of Aviloo, said the partnership is about creating confidence for both buyers and sellers.
“The uncertainty about the condition of the battery – the most important factor influencing the residual value of a vehicle – is a significant challenge for many buyers of used electric vehicles. We want to create clarity in the global market for used EV and plug-in hybrid vehicles, both for dealers and potential buyers. Therefore, we are very pleased to have found a strategically important partner in Manheim Australia. We are confident that through this partnership, we have taken another step towards elevating battery diagnostics in Australia to a new level.”
Manheim’s global parent, Cox Automotive, already has deep experience in EV remarketing. In the United States, Manheim sells around 80,000 EVs per year and has issued VIN-specific health scores on more than 50,000 units.
What It Means for Fleet Managers
For Fleet Managers, the introduction of battery testing offers several tangible benefits:
- Stronger resale values: Certified battery health increases trust and bidding activity at auction.
- Faster turnover: Vehicles with SoH certificates sell more quickly, reducing holding costs.
- Better forecasting: Greater transparency helps refine WOLC models and align them with actual market performance.
- Improved procurement cases: Stronger residuals support internal business cases for EV adoption.
For Sustainability Managers, the move supports organisational goals to reduce emissions by making EV transitions more financially viable. For Finance Managers, it reduces the residual value risk that often complicates investment approval.
Looking Ahead
Battery health certification will likely become the industry standard for remarketing EVs. Just as a full service history became a non-negotiable for ICE vehicles, Fleet Managers can expect that SoH certificates will be demanded by both wholesale and retail buyers.
For now, Manheim’s rollout with Aviloo provides an early advantage to organisations consigning EVs through its auctions. As volumes of de-fleeted EVs grow, those who embrace battery certification will be better placed to maximise value and accelerate fleet transitions.
Key Takeaways for Fleet Decision Makers
- Battery health is the number one factor influencing EV residual values.
- Manheim now offers Aviloo SoH testing at auction, with certificates attached to listings.
- EVs with certificates sell faster, attract more bids and command higher prices.
- Buyers are willing to pay $1,000–$2,000 more for certified EVs.
- For fleets, this helps improve WOLC models and strengthens the EV business case.
At a time when fleets are under pressure to reduce emissions and demonstrate financial responsibility, initiatives like Manheim’s battery health testing could be the catalyst to unlock faster EV adoption.
