7.4.2.2 High-energy battery systemThe no load SOC loss shall be measured with a complete and fully operational battery system. The BCU shall be supplied with the necessary auxiliary power (e.g. 12 V d.c. power supply) in order to be able to control necessary battery system functions during the rest period, for example: — battery system cell balancing; — periodical BCU wake-up activities. The no load SOC loss rate[s] shall include any possible parasitic or operational discharge contribution of the cell balancing circuitry itself beyond the inherent self-discharge rate of the battery cells themselves. The no load SOC loss rate of the battery system shall be measured for three different rest periods and at two different temperatures. The battery system shall be conditioned to 100 % SOC by a standard cycle (SC) and then left at open circuit for a certain time. The BCU shall be able to perform control activities (e.g. cell balancing, regular wake-up activities). After the rest period, the remaining SOC shall be determined by a C/3 discharge at RT.