APS-300 Instructions
Page 5
500-33315_A
Battery Selection
The table below shows typical standby time in hours for various loads and batteries. The table works for either 12V or 24V
batteries. The APS-300 has been evaluated by UL with an 18Ah sealed lead acid battery for 12V and (2) - 9AH batteries for 24V
to meet the 4 hour stand by requirement.
Note: UL requires a minimum of 4 hours of standby time for Commercial Mercantile Burglar Alarm. The table below has the
required battery size highlighted (*) to provide this 4-hr stand by time under a full rated load.
Approximate Battery Standby Time Table with a reserve of 3 Amps for 5 minutes for Alarm
AH = Amp Hours Capacity at a 20 hour rate - Hrs = Hours
Total Output
Amps
4Ah Battery
Standby
7Ah Battery
Standby
9Ah Battery
Standby
18Ah Battery
Standby
24Ah
Standby
1A
2.92 Hrs
5.32 Hrs
7.79 Hrs
15.89 Hrs
23.65 Hrs
1.4A*
2.09 Hrs
4.75 Hrs
5.56 Hrs*
12.61 Hrs
16.89 Hrs
2A
1.46 Hrs
1.3 Hrs
3.46 Hrs
7.94Hrs
10.64 Hrs
2.8A*
1.04 Hrs
1.9 Hrs
2.47 Hrs
5.04 Hrs*
7.60 Hrs
The Battery recharge time is 2.6 hours for each 1 Ah Amp Hour of battery capacity with either 12V or 24V batteries. The
minimum battery capacity is 4Ah and the practical limit is 24Ah UL evaluated with an 18Ah battery on the 12V configuration and
(2) 9Ah batteries on the 24V configuration. Please see the Figures for 12V configurations and 24V configurations below in this
document. UL Listed systems require that if standby batteries are to be used they must have a 4 hour capacity under the full
rated load.
Recommended Maintenance
The power supply and stand by battery(s) should be tested at least once a year as follows:
1. Check LED’s for normal state. AC ON Green and DC ON Red.
2. Check output voltage with normal load. With AC ON for 12V setting, DC output voltage should read between 12.83VDC-
13.69VDC and 27.1 - 27.4VDC on the 24V setting.
3. Check DC Output Amps to be sure it complies with output rating.
4. Disconnect AC input. AC LED should be off, and the DC LED’s should remain normal.
5. Check DC Output to be above 11.5VDC for 12v setting and 23.0VDC for 24V setting. This checks standby batteries to be
operational. Sealed lead acid batteries have a typical life of 3 to 5 years. Test battery by itself as outlined in your battery
instructions to be sure the Amp hour capacity is within proper range.
6. Re Apply AC and verify AC LED ON.
