very small battery backup

[jeromephone 6]

I am working on a system that will use some netgear POE switches which will be housed in Lcomm plastic enclosures about 14X6X12 . I would like to put a small battery backup in the same houseing as all I will have is the switch, incoming cables and possibly a fan. the switch runs on 7.5 v and the fan would be 12. I have been looking(google) for UPS as small as 150va. The backup time i need is just around 5 min as these will be on generator power within that time. I would like something that could use a 7 amp hr battery.

[Soundy 1]

Why not just put a 7Ah battery in there, run the fan directly, and use a voltage regulator for the switch?

 

This unit will take whatever AC or DC input you provide, give you 6/12/24 or adjustable DC output, keep the battery charged, and automatically switch over to battery on power failure:

http://www.electronicproductonline.com/catalog/product_info.php?manufacturers_id=85&products_id=1770&osCsid=8a03cf580a819292c1d4a8f99e75cbc3

 

We get them off-the-shelf at ADI; the link above is the only place I've ever found them listed online.

[NotoriousBRK 0]

If you can run everything off a 12V bus, you can just use a simple 7Ah battery, and a $15 solar charge controller. The charge controller keeps the battery topped off, and provides a battery-backed 12V power source if the main power supply fails (like when power goes out).

[jeromephone 6]

thanks for the reply I will order this board tomorrow and give it a try. If I get it working I will post a pic.

[Soundy 1]

Do keep in mind, you need to consider the current requirements of the switch, and make sure the regulator is sized appropriately. The one I linked there will only provide up to 3A; if the switch needs more than that, you'll have to find another option.

[thewireguys 3]

Why not use Din-rail gear?

 

[jeromephone 6]

that looks even better. What are the specks or who is the supplier. I looked at my switch requirements and the 4 port poe is 44 watts max I found another switch that is a five port with one uplink (BV-tech 4+1 with up to 65 watts POE.

 

Thanks for your help.

[thewireguys 3]

I just built a bunch of L-Com boxes with din-rail power supplies and din-rail POE switches..... so nice to install.

 

I didn't use a UPS in this build but I have room to expand.

 

http://www.emersonindustrial.com/en-US/egselectricalgroup/products/control-power-solutions/power-protection-conditioning/Pages/default.aspx