Technical "expert" at Citroen told me I should visit my dealer to do a battery optimization. He explained that every couple of years every c-zero should be connected to a tester, which needs about four hours to finish the process. He claimed that range and battery health should improve significantly after optimization. The most interesting part of what is going on during the optimization is repeating raising the cells voltage to 4,2V for a very short time. I hardly believe it should be good for battery since 4,2 is quite dangerous voltage for Li-Ion cells.

After 3 years and 83.000 km I notice about 15% of capacity drop so it sounds interesting to me.

Did anybody go through battery optimization and if so, what was the result?