SoH Readout is NOT a Battery Test

In the absence of a precise SoH specification, the user has to ask himself three questions with regard to the above SoH sources...


The buyer of a new electric car assumes a State of Health (SoH) of 100%. This means that the battery is completely healthy and designed to allow the vehicle to achieve the stated range. Over the course of the vehicle's life, the SoH always receives attention as the key performance value for battery health.
As a solution to this, some apps offer their services and present the user with a (supposed) SoH of their vehicle. Alternatively, it is possible to have the SoH read out in the workshop.

In the absence of an exact specification for the SoH, the user must ask himself three questions with the above SoH sources:

  1. What is the basis for the SoH? A read-out SoH is the SoH assumed by the battery controller, i.e. the number used for range calculation. This is a calculated value and often does not correspond to reality.
  2. Where does the data come from on the basis of which the SoH was determined? Is the SoH based on some kind of estimate or extrapolation? What data is used in these calculations?
  3. What exactly does the SoH show: drivable energy, drivable and usable energy, or just usable energy? The difference is whether you get a report on the total available energy or only on the energy used for driving, while the energy used for radio, air conditioning or other activities in sleep mode is excluded.

These are exactly the questions that the AVILOO PREMIUM Test addresses:

  1. What is the basis for the SoH? The data for the AVILOO PREMIUM Battery Certificate comes from a real test in which the traction battery is run down from 100% state of charge to 10% state of charge during normal everyday driving.
  2. Where does the data come from? During a PREMIUM test, we process and collect millions of real data points through the AVILOO Box, a device connected to the car's OBD port. Then we cross this real data with equally real data that we have measured through thousands of tests. Details are very important to us, e.g. when the battery cells were produced and from which series they come. For the purpose of accurate and secure data processing, we have developed a special software, a learning machine. Standard factors such as temperature compensation and internal resistance are included in the analysis.
  3. What exactly does the SoH show? The SoH of the AVILOO battery certificate represents the drivable energy. This means that the AVILOO certificate indicates the percentage of net extractable energy that could be used to drive a car.

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