Technical Info

Back-Up Battery Calculations

This calculator is a guide to determining the required back up battery capacity of your system. 

Total DC load is the total Current drawn by the equipment installed based on 24V DC supply.

Back up duration for full load consumption is based on average duty cycle of the audio ( typically 20% for speech ) and the duration required is based on the Consultants' / Authority requirement, typically 0.5 to 1 hr. Standby duration is normally 1 to 3 hours.

Download the calculator 

Connections of small loads

This is an example for connecting back up supply for small loads, typically less than 25A at 24V DC.

The power packs linked in series to form 24V, shall be terminated at BC9740 Battery Charger's BATT IN terminals and thereafter to PS9400 Power Supply's Batt connectors.


Ensure that the appropriate size of connecting cables are used to suit the total loading. In this setup, we recommend 2.5mm with high temperature PVC insulation cables.