In starting sequence with system battery flat/faulty

When terminal 15 is detected, the voltage here of the system battery (55 Ah) must be >1.5 volts and the electronic disconnecting switch closes for 30 seconds. Electrical system is thereby supplied via starter battery (110 Ah). The starting sequence must now follow within this period of 30 seconds. Starting sequence can be repeated several times by detecting terminal 15 again. If system voltage is < 1.5 volts: starting is no longer possible.