CNES, ESA and SAFT have initiated a life testing evaluation on lithium-ion batteries. Several batteries each made of six 40 Ah cells are submitted to real-time and accelerated geostationnary cycling at various DOD. Two batteries are undergoing accelerated tests with a maximum DOD of 50% corresponding to the STENTOR missions. One has already achieved more than 7 simulated years and the other more than 5 years. Preliminary results concerning real time and accelerated test at higher DOD are also presented.