INTA-SPASOLAB as independent testing facility for more than 25 years has an extensive expertise in the certification and qualification of photovoltaic devices for space applications. Recently INTA-SPASOLAB has participated in the qualification of the latest technology upgrade of lattice-matched III-V GaInP/GaInAs/Ge triple-junction (TJ) bare solar cells manufactured by AZUR SPACE Solar Power GmbH (Germany). This participation has consisted of carrying out test sequences of subgroup B, Beginning of Life (BOL) performance, C1 (Electron Irradiation) and P (Proton Irradiation) according to the current ECSS E-ST-20¬08C, Rev.1 reference standard.At these subgroup qualifications, some performance tests, in particular spectral response and electric performance tests, have been agreed to be either modified in the test sequence order or added, in order to understand better the evolution of the electrical cell parameter results.In this work, test sequence variations and obtained results on those subgroups B, C1 and P, are presented. The gained experience at this qualification and other previous work about solar cell characterization is used to suggest amendments.