A Bosch B series panel showing "Missing Battery" on the keypad and the Battery Light on the B series panel lite solid, indicating a missing battery.
This problem most likely occurring after a power outage, or upgrade from a D series panel.
If alarm panel is connected to an auxillary power supply, that power supply may be drawing power from the AUX power connection. The D series panels would allow the AUX power port to both charge the extra batteries and receive power back to the panel via the AUX terminal. B series panels do not allow for this type of external battery charge/discharge configuration.
You will need a B520 power supply to serve as a replacement power supply module. You will have to re-route devices that are currently powered from the AUX terminal to the AUX PWR port on the B520.
We upgraded a Bosch D series panel to a new B series. Their was no immediate problem until the client had a power outage. After the power returned, the extra battery charge triggered the panel to shut off all battery charge voltage. The panel then acted as if their was no battery even-though when AC was removed, the panel operated on battery power.
The picture below is the power supply that is NOT COMPATIBLE with B series Bosch Panels. The power supply is the vertical mounted device in the lower right of the panel.