Installation Manual

411UDAC Document #51073 Rev. D 12/09/2008 P/N 51073:D 65
Battery Calculations
CHAPTER 6 Battery Calculations
Use the Total Standby and Alarm Load Currents calculated in Table 6-2, “Load in Standby,” on page 66, and Table 6-
3, “Load in Alarm,” on page 66, for the following battery calculations.
1. Select a battery with an Amp Hour rating greater than that calculated in Table 6-1 .
 NFPA 72 for Central Station and Proprietary Protected Premises systems require 24 hours of standby
 NFPA 72 for Auxiliary and Remote Station systems require 60 hours of standby (14 Amp Hours)
2. Two 12 VDC, 7 Amp Hour batteries, wired in parallel, can be located in the backbox to provide 14 Amp
Hours of backup (refer to Figure 2-5 on page 22 for battery cable connections)
TABLE 6-1: Battery Calculations
Standby Load
Current in amps
(from Table 6-2 )
[ ]
X
Required Standby Time in Hours
(24 or 60 Hours)
[ ]
= __________
Alarm Load
Current in amps
(from Table 6-3 )
[ ]
X
Required Alarm Time in Hours
(i.e. 5 min. = 0.084 Hours)
[ ]
= __________
Add Standby and Alarm Load for Required Ampere Hour Battery __________
Multiplying by derating factor of 1.2 X1.2
Total Ampere Hour Battery
1
= __________