Check Battery Condition: Professional Diagnostics for EVs

The battery is the most expensive component of an electric vehicle and often accounts for up to 40 percent of its total value. Nevertheless, many buyers rely on the simple percentage display in the cockpit, the so-called State of Charge (SoC). However, this only indicates the current fill level, not the remaining total capacity or the chemical wear of the cells. To determine the actual market value, establishing the State of Health (SoH) is essential.

A professional battery test uncovers hidden defects that can arise from frequent fast charging or thermal stress. Without such a test, there is a risk of acquiring a vehicle with an already heavily degraded battery, which can result in high follow-up costs. DIAVAG offers an independent solution for this that is not tied to workshops or vehicle manufacturers. This guarantees an objective assessment with no self-interest in repair orders or vehicle sales.

The Premium Battery Test used by DIAVAG delves deep into the vehicle's system architecture. While conventional inspection organizations often only read out superficial data, our standardized workflow includes a detailed analysis of various parameters. This includes measuring cell balance, i.e., the voltage differences between individual battery cells. Larger deviations can indicate a defect or uneven aging.

In addition, kWh capacity, internal resistance, and the charging curve are evaluated. The appraisers use calibrated hardware consisting of an OBD2 scanner and a specialized battery diagnostic device. This combination makes it possible to capture real-time parameters during the discharge or charging process. The result is a precise SoH value as a percentage, comparing the current condition to new condition. This data is highly relevant for insurers, banks, and courts, as it provides indisputable proof of the actual technical condition.

A key advantage of the DIAVAG model is mobility. You don't need to arrange an appointment at a specialized workshop or transport the vehicle at great expense. The appraiser comes directly to the location of the asset, whether that's your home garage, a dealer's yard, or a public parking space. In the regions of Hamburg, Berlin, and Munich, we guarantee an appointment within 24 hours.

Pricing is completely transparent. For the inspection of an EV including the Premium Battery Test, a fixed price of auf Anfrages applies. This amount includes the callout within the regions, the on-site inspection, and the preparation of the BVSK-compliant PDF report. There are no hidden costs or hourly billing. This cost certainty is especially important for private customers and lawyers who need clear cost structures in cases of inheritance or divorce.

A report is only as valuable as its legal robustness. DIAVAG therefore applies the highest qualification standards. All appraisers work according to the guidelines of the Federal Association of Independent Automotive Experts (BVSK). In addition, the inspection body is certified to ISO/IEC 17020 Type A, representing the highest level of independence. Such a report is signed by a senior inspector, making it usable in court.

In legal disputes, such as warranty claims after a used-car purchase or value determination for insurers, this standard offers the necessary security. For complex legal questions, we always recommend consulting a lawyer or notary, for whom our report serves as a well-founded technical basis. Optionally storing a notarial hash on the Polygon blockchain also ensures that the document cannot be tampered with after the fact.

The comparison clearly shows that classic inspection organizations, while enjoying high reputation, often do not offer the necessary depth in battery diagnostics for all asset classes. Algorithm-based services, on the other hand, provide only estimates without a physical inspection of the vehicle's condition, which is insufficient for a legally sound assessment.

Regulatory requirements for battery data transparency are constantly increasing. From February 2027, the EU Battery Passport will become mandatory for all new batteries in electric vehicles and stationary storage systems. This digital passport is meant to contain information on origin, composition, and the condition of the battery. DIAVAG is already prepared for these requirements today and integrates relevant data points into its reports.

For EV owners, this means that regular documentation of battery condition secures resale value in the long term. Anyone already relying on standardized testing procedures today will be able to present a seamless history once the new regulation takes effect. This is a decisive competitive advantage in the used market, since trust in battery longevity remains the main criterion for buyers.

An often underestimated area is the assessment of stationary PV home energy storage systems. In real estate transactions or inheritance cases, the question frequently arises as to what value the installed solar technology still has. Since home storage systems are technically closely related to EV batteries, DIAVAG uses the same high-quality hardware for their analysis. Here too, the Premium Battery Test is used to assess the remaining capacity and safety of the storage system.

The fixed price for testing a home storage system is also auf Anfrages. This includes the on-site inspection, measurement of electrical parameters, and preparation of a detailed condition report. Especially in warranty disputes with manufacturers, an independent report provides the necessary facts to assert claims. Here too: DIAVAG is not an installer and does not sell storage systems, which guarantees the neutrality of the findings.

For commercial customers such as car dealerships or fleet managers, DIAVAG offers scalable solutions. From a volume of 50 appraisals per month, individual terms can be agreed. A central component here is API integration with existing Dealer Management Systems (DMS). This enables a seamless workflow from commissioning through to integrating the finished report into vehicle marketplaces.

Dealers benefit from faster stock assessment and greater credibility with end customers. DIAVAG also offers a hardware case including software for auf Anfrages, with which independent appraisers or workshops can carry out the standardized inspection process on their own. Final review and signing of the report is still carried out by DIAVAG's senior inspectors to maintain the high quality standard.