The Power Box June 2006

To run the various stuff in the office I had a pair of 12v power supplies, one plugged into a UPS that was burdened with the main computer. And a dozen 12 volt wall wart DC power packs. This was a picture of inefficiency.

My goal is to create a separate system of a battery backup for all the 12v items on the desk, and leave the UPS to powering the big computer & it's monitor.

As usual, this project will be made up of junk parts, excess scrap and other stuff.

Parts

• One SCSI drive case - free in a swap.
• 6 gel cell lead acid batteries. $5 ea
• PowerGate Isolator - HRO

Four bay SCSI drive case

Back of case

Take the cover off

There were no drives in this old case. Just a power supply and some cables

Out go the unneeded parts

In  go some batteries

Four batteries take up the bottom of the case

One strip of cardboard between the rows of batteries, wire ties hold them secure.

 I drilled holes in the case bottom for the ties to pass through.

To fit two more batteries, I need a shelf to hold them above the lower ones. A dead CDROM comes in handy here. Pop the metal cover off of the chassis.

CDROM drive turned shelf goes in the bay

Now I have a shelf

Two more batteries and begin the wiring. Using some 10 gauge insulated wire and TNT connectors. Who still calls them TNT connectors?

Safety measure, cover the battery terminals.

Next is the battery isolator. This will charge the batteries and switch from AC-DC power supply to batteries so the radio gear & computer network will stay up in a power failure.

To mount the isolator I have this scrap drive adaptor that I will trim and drill mounting holes for.

Trimmed up and ready.

I held the drive adaptor up to the case a marked where to drill.

Mounted the isolator shelf with HDD screws.

Overhead view. Fan is functional.

Pwrgate Isolator. This uses Anderson Power Pole connectors.

I installed Power Pole connectors on the battery wires, rigged up a Power Pole feed from the bench power supply and another Power Pole jumper to a distribution panel.

All the 12volt items on the bench are now powered from the backup battery system. A few other 5 volt item are fed from the computer or monitor USB ports. Very few DC power packs left plugged in.

Six batteries make this a little heavy - I added a pair of gate handles for easier lifting.

Use shortest screws I can. Refer back to the cardboard insulator on the upper battery deck.