The data-based status report of the traction battery
Forecasts about the lifetime of a traction battery are often inaccurate
The actual battery condition of a traction battery cannot be reliably determined without a manufacturer-independent diagnosis. However, electric vehicles themselves provide information on the battery condition. Nevertheless, practice shows that the "state of health" provided by the battery's management system often deviates greatly from the reality. As a result, forecasts about the remaining lifetime and performance of a traction battery based on this information are often inaccurate.
The aging of a battery depends on the individual use
Traction batteries of electric vehicles nowadays mostly consist of lithium-based accumulators such as lithium-ion ones. Such lithium-ion batteries age: the residual capacity of the batteries decreases over the years. Experts distinguish the aging process according to a calendar aging and a cyclic aging.
In calendar aging, various factors such as temperature and state of charge influence the aging process. For example, the "feel-good" temperature of a lithium cell is around 20 degrees celsius. If the cell is permanently stored at 30 degrees celsius, for instance, it ages around twice as fast as at 20 degrees celsius. The state of charge also has an influence on calendar aging. The ideal state of charge for storing a lithium battery is around 50 percent of its maximum capacity. Both long-term storage at the maximum state of charge and storage at 0 percent state of charge lead to a reduced service life.
Cyclic aging results from the driving and charging behavior. In terms of driving behavior, a sporty, aggressive driving style with strong acceleration when starting and rare regenerative braking results in higher stress on the battery. During the charging process, frequent use of fast charging options also places a greater strain on the battery. On the other hand, a forward-looking driving style is gentle on battery aging - for example, by planning the optimum charging method at an early stage.
How the Battery Quick Check works
The electric car is connected to a mobile charging station and a diagnostic tool is connected to a vehicle's on-board diagnostic system via the OBD2 interface.
Qualified workshop personnel or TÜV Rheinland experts read out all relevant data via the interface in about one hour.
The battery data is then sent to the BQC cloud.
In the cloud, intelligent algorithms estimate various battery parameters and compare the behavior of the battery measured in the vehicle with the stored models.
The result is an independent and precise status report on the traction battery - the Battery Quick Check Report.
The central value - SOH (State of Health)
The central value in the status report is the battery's capacity in percent (called State of Health or SOH). The 80 percent mark is a reference point: if the capacity drops to this value, the battery can generally no longer be used effectively in the vehicle. On the other hand, the closer the capacity is to 100 percent, the higher the residual value of the battery.
In addition to the SoH value, the battery report contains other battery and vehicle parameters, such as battery temperature or mileage, which describe when and under what conditions the battery evaluation took place.
How does the Battery Quick Check affect the residual values?
With a battery report in the appraisal for all pre-owned BEVs, the average residual values will increase.
Who can benefit from the Battery Quick Check?
Battery Quick Check provides a basis for valuation wherever the residual value of a BEV plays a role: with leasing returns, with any change of owner, with a transfer of liability, etc.
In the future, pre-owned car buyers should demand certification of independently assessed battery quality to protect themselves.
Pre-owned car sellers, in turn, should present a certificate in order to obtain the maximum resale price.
Fleet and leasing firms can work together with fleet managers to create incentives for better battery use, similar to mileage-based incentives.
How long does a Battery Quick Check take?
The duration of the Battery Quick Check depends on the battery size and the maximum possible charging power and therefore differs for different vehicle models. It can be performed for most vehicle models during a 60 to 90 minute workshop visit.
Can any workshop conduct a Battery Quick Check?
After the product launch, we will increasingly expand availability so that every workshop can carry out the Battery Quick Check.
Can private customers also obtain a Battery Quick Check with a certificate?
Initially, we are offering the Battery Quick Check only to commercial customers. If necessary, private customers will eventually be able to obtain the service through their automotive repair shop or independent garage.
Does Battery Quick Check GmbH guarantee the residual capacity and/or service life of a tested traction battery?
No, because we always certify the SoH at the time of the test. The subsequent evolution of battery capacity and service life depends on how the individual driver uses the battery.