Bosch Appliances Home Security System D7212G User Manual

D7212G

Page 27

© 2003 Bosch Security Systems

4998138544C

4.2.4

Battery Supervision

When the battery voltage drops to 13.8 VDC, the yellow Charging Status LED lights. When the battery drops to 12.1 VDC,
the red Low Battery LED lights and the panel, if programmed for power supervision, transmits a 

BATTERY LOW

 report in

the Bosch Security Systems Modem IIIa

2

  Communication Format.  It transmits a 

TROUBLE ZN 9

 report in the BFSK

format.

If the battery is missing or shorted, the red Low Battery LED flashes at the same rate as the green Operation Monitor LED. If
the panel is programmed for power supervision, it transmits a 

BATTERY MISSING

 report in the Bosch Security Systems

Modem IIIa

2

  Communication Format, or 

TROUBLE ZN 9

 report in  the BFSK format.

When battery voltage returns to 13.7 VDC the Low Battery LED goes out.  If the panel is programmed for power
supervision, it transmits a 

BATTERY RESTORAL 

report in the Bosch Security Systems Modem IIIa

2

  Communication

Format or 

RESTORAL ZN 9

 report in the BFSK format. At 13.9 VDC the Charging Status LED goes out.

Investigate low battery reports immediately: If primary (AC) power is off and the discharge continues, the panel becomes
inoperative when the battery voltage drops below 10.2 VDC.

4.2.5

Battery Charging Circuit

Float Charge

The float voltage for the battery charging circuit is 13.5 to 13.9 VDC at a maximum current of 1.4 A. If float voltage drops
lower than 13.5 VDC, the Charging Status LED will illuminate.

Loss of AC Load Shed Relay protects battery: During an AC power loss the battery supplies all power to the security system. If
the battery voltage falls below 10.2 V during an AC power loss, a “load shed” relay isolates the battery from the panel and
disables the panel. Load shed protects the battery from being damaged by deep discharge. When AC power restores, the load
shed relay resets and battery voltage is again available.

Overcharge Load Shed With AC Present: If more than 1.4 A of current draw from the panel is detected, the panel shuts down.
Remove all loads to the panel and disconnect AC power. Add a new battery and reconnect AC power.

Reset the panel by momentarily placing the reset pin in the disable position. See Figure 4 on page 22. The red Low Battery
LED continues to flash until the panel is reset.

A shorted battery condition is created either by a shorted cell inside the battery or by a short on Terminals 4 and 5. A shorted
battery may generate 

WATCHDOG RESET

 reports.

4.2.6

Battery Discharge/Recharge Schedule

AC OFF

AC fail report when AC fails if
panel is programmed to report
AC failure at occurrence.

AC ON

Load shed relay resets, battery
charging begins, battery trouble
and AC restoral reports sent.

13.9 VDC

Charging float level.

13.7 VDC

Battery restoral reports sent, Low
Battery LED off.

13.8 VDC

Charging Status LED on.

13.9 VDC

Charging Status LED off, battery
float charged.

12.1 VDC

Low Battery & AC fail reports if
programmed; Low Battery LED
on.

10.2 VDC

Battery load shed (processing
functions continue if AC is
present).

Power Supply