BBU Selector Tool

Battery Backup Unit Calculator

48V DC System Comba Telecom
01 Runtime Requirement
Type any value or choose a preset
02 BDA 1 *
BDA 1 is required.
03 BDA 2 — optional
Output
> Awaiting input...
> Select runtime & BDA 1
> Press Calculate BBU
Option 1 — Dedicated BBU per BDA
BDA 1
Required BBU
— Run time —
Power— W
Current— A
Capacity— Ah
BDA 2
Required BBU
— Run time —
Power— W
Current— A
Capacity— Ah
Option 2 — Shared V2 BBU
Combined
Required BBU
— Run time —
Power— W
Current— A
Capacity— Ah
Calculated Run Time Formula
Battery Run Time = Battery Capacity (Ah) Total Current Draw (A)

BBU Calculator Tool Instructions

This tool is designed to select the required Comba battery backup unit model number based on the required BDA equipment and required backup runtime.

  1. Select the required backup runtime.
  2. Select the equipment and quantities requiring battery backup power.
  3. Click "Calculate BBU" to return the result. The tool provides up to 2 different options:
    • Option 1 — used if independent BBUs are needed for each BDA selected.
    • Option 2 — may be used if the AHJ permits using a single BBU to power 2 × BDAs.
  4. If the tool returns an "Out of Range" result, the total required battery capacity exceeds Comba's maximum battery capacity of 100 Ah.
Special Notes

Only the Comba Version 2 BBU supports providing power to 2 × V3 BDAs. In this case, and if permitted by the local AHJ, a single APV3-BDA can be connected to the Version 2 BBU to support a summary of both BDA alarms.

If the local AHJ requires dedicated annunciator alarms per BDA, then 2 × APV3-BDA should be used.