»AIR«: Drive battery inspection using X-rays

The prevalence of fully electric vehicles has risen sharply since 2020. According to figures from the Federal Environment Agency, only around 63,000 units were sold in 2019, compared to around 524,000 vehicles in 2023, almost nine times as many. As a result, the market share of fully electric vehicles also increased significantly from 1.8% in 2019 to 18.4% in 2023 within four years. Even though there is still a long way to go before the German government's target of 15 million electric vehicles by 2030 is reached, electromobility is becoming increasingly popular.

So far, the well-founded assessment and condition evaluation of the traction battery - for example of a used or damaged vehicle - is only possible in a very rudimentary way. In particular, this is dampening confidence in the technology and inhibiting the used car market in the electric sector.

The AIR X-ray system has the potential to become the standard tool for the objective assessment and evaluation of electric vehicles - after all, the traction battery is by far the most expensive component of the vehicle. The new system is specifically designed to meet the requirements of the fastest and most cost-effective testing possible, which promotes uncomplicated accessibility of the technology and enables rapid market penetration. The measurement time per vehicle is currently around ten minutes, which allows uncomplicated integration into existing testing processes.

Comments on the project

Michael Salamon, Fraunhofer IIS: »For the first time, AIR technology makes it possible to carry out a detailed inspection of the vehicle underbody quickly and easily. By focusing the technology on the life cycle of vehicles, Fraunhofer IIS is doing pioneering work as part of a strategic initiative to increase confidence in the still young technology and thus promote the emerging used car market, among other things.«

Prof. Klaus Böhm, Munich University of Applied Sciences: »AIR has the potential to revolutionize the preparation of expert opinions in the context of electromobility - and beyond. The described limitations of the methods used to date can be significantly expanded by incorporating AIR into a multidisciplinary approach. This will contribute to a reduction in repair costs for electric vehicles. More accurate and reliable appraisals can also lead to more predictable used car processes and lower insurance premiums for electric vehicles.«

In 2024, over 100 private vehicle owners participated in the pilot project with their electric cars. More than 20 vehicle types were scanned. The AIR X-ray system made all drive batteries visible, regardless of their installed position and battery type, as evident from the examples (a) Tesla Model 3, (b) Renault Zoe, (c) Volkswagen ID3, (d) Hyundai Ionic 5, (e) BMW i3, (f) KIA eSoul, (g) Peugeot e208, (h) Mini Cooper E, (i) Jaguar iPace. 

Damage assessment 

A Volkswagen e-Up exhibited visible damage on the passenger side. The X-ray image shows the deformations, including the penetration depth. The structure of the battery frame and surrounding chassis parts is also recognizable. In an enlarged image, it is evident that the area around the battery compartment shows no significant deformations.

More severe deformations were noted in this Volkswagen e-Up, which was specifically crashed at 50 km/h by DEKRA and the KTI for the Würzburg bodywork and damage days. The accident vehicle was a total loss with massive front damage, bent longitudinal beams, and heavily deformed bodywork on the left side. However, the high-voltage storage remained intact, as confirmed by the X-ray differential image analysis.