MobilHybrid cannot be started, deep discharge

If the battery voltage is below 43V per battery set, charging the battery is no longer possible. Only the function of the changeover relay is still active. The undervoltage cut-off can be interrupted for 15 minutes with the "ABS_Off" button. It is important that a three-phase power source is applied to the generator or grid input with your clockwise rotating field; now the MobilHybrid will charge normally again.