The ADAC has published the results of a battery endurance test of the VW ID.3. The Allgemeiner Deutscher Automobil-Club (ADAC) is Europe's largest automobile association, providing roadside assistance to members. A pre-facelift version of the ID.3 with a 77 kWh battery was chosen for the test, with the EV charged to 100% each time.
The ADAC notes that the power pack has a gross capacity of 82 kWh, with this buffer aiming to increase battery longevity. The study monitored the deterioration of the ID. 3's battery over 100,000 km (~62,137 miles), taking two and a half years. After this time, the BMS showed the battery had a 93% state of health (SoH), a 1% reduction for every 14,286 km (~8,877 miles). This is far greater than Volkswagen's 74% estimate for the same mileage, which equates to 1% lost every 3,846 km (~2,390 miles).
For comparison, Tesla estimates that an average battery in one of its EVs loses 12% capacity after 322,000 km (~200,000 miles); that's around 1% per 26,816 km (~16,667 miles). The ADAC is continuing the test until 160,000 km (~99,419 miles) are reached and the manufacturer's warranty expires. It is worth bearing in mind that this test was run on just one car, meaning caution should be taken when drawing conclusions.