The model accuracy is calcu­lated from a set of valida­tion exper­i­ments that cover the total opera­tional area of the cell as speci­fied by the cell manufac­turer. Additional valida­tion measure­ments in the inter­po­la­tion and extrap­o­la­tion regime, that are unknown to the model creator, are used for additional testing of the model. The ratio of the measure­ment time between the different valida­tion sets is as follows: valida­tion set known to Batemo and competitor 50%, valida­tion set known only to Batemo and unknown to competitor 25%, valida­tion only know to competitor and unknown to Batemo 25%. Model accura­cies are defined and averaged as defined in the Batemo valida­tion Excel documents.