Battery Connection; Low Voltage Disconnect Feature - GE MDS 4790M Installation And Operation Manual

MDS 05-3628A01, Rev. B

Battery Connection

To connect the backup battery cable, follow these steps:
1. With no AC power applied, remove the 4 Phillips screws on each side of
the chassis and remove the top cover of the radio.
2. Connect an antenna or RF load to the radio's RF output connector. (This is
necessary because in most cases, the radio begins transmitting as soon as the
battery is connected.)
3. Locate the battery cable and plug it into the matching connector on the
Battery Control Board. (See Figure 10.)
When connecting the backup battery cable, be careful not to short the battery
charging cable or the battery "+" terminal to the radio chassis. Doing so can
cause damage to the battery and possible personal injury.
4. Reinstall the top cover, and re-apply AC power to the radio. Be sure the
power supply switch(es) are set to ON.
NOTE:
If AC power is not connected, or the power switches are set to OFF,
the radio will operate on battery power until the battery becomes
discharged (approximately 1 hour). When shipping or storing the
radio, the battery cable should be disconnected.
Figure 10. Location of Backup Battery Cable

Low Voltage Disconnect Feature

The Battery Control Board contains a Low Voltage Disconnect circuit. It prevents
damage that may be caused by having a backup battery drop below 10.65 volts
when it is powering a radio, such as during an extended AC power outage.
When the battery voltage drops to 10.65 Volts (± 0.2V), the Low Voltage
Disconnect assembly automatically disconnects the battery from the radio. This
stops operation of the radio, but protects the battery from potential damage.
When AC power returns, the battery is automatically connected to the power
supply for re-charging and normal radio operation resumes.
MDS 4790M (MPT 1411) I/O Guide 15