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w6bi's picture

I'm using a Ubiquiti ToughSwitch (5 port) to power my nodes.  It's powered by a 24VDC brick, and I'd like to replace that with some sort of "UPS" to get through power outages.  Any recommendations?

K5DLQ's picture
If you want 110V UPS, then

If you want 110V UPS, then any standard UPS should do fine.  There is very little power draw from these adapters.

AE6XE's picture
So here's a possible idea.  

So here's a possible idea.   Haven't tried this, so maybe someone will shot a hole in this...    

Buy a deep cycle battery(s) and a solar charge controller with out the solar panel.   Can get one with PWM charging profile--renolgy has basic ones for like $30.    Hook the ubnt brick as if it was the solar panel into the charge controller.   Put the nodes on the load side and the battery(s) on the charge controller--will trickle charge all the time with the right controller.   The ubnt brick won't have sufficient voltage level or capacity to do more than trickle charge, but might still work--option to upgrade the power supply.  When the power goes out (like the sun going down), the batteries take over.  Low voltage shutdown for these low end renolgy controllers is 11.1vdc (probably 22.2vdc for 24v system).   


km5l's picture
Joe, I like your idea
This goes back a year, but we're at this crossroad.  For field deployments, do you still like your idea above? Questions/Details: Someone else suggested a "50 amp wheelchair battery" - presuming this is much less weight. Then a 40 watt solar panel and a 45 watt charger. I've never personally worked with any of this stuff, so trying to do the right thing here.

I'm not following your statement "hook the ubnt brick as if it was the solar panel into the charge controller", etc. Isn't that the 120V input to the brick? I might need a picture! :)
Patrick KM5L
AE6XE's picture
Patrick,  the idea was best
Patrick,  the idea was best fit for when there is 110vac or other power source to plug into, and it fails.  Then a battery takes over until the power returns (a low cost UPS).    For the "field deployment" you are thinking of, is it the opposite?  There's no power source and a battery configuration is primary, with optional solar power to run 24x7?

For the UPS setup above, the 24v of the ubnt power brick would be plugged in place of a solar panel into the charge controller.   

km5l's picture
should have figured that out
Thanks Joe, totally misread the post. - it's a good idea though as far as the purpose.

Patrick KM5L
If your running a standard

If your running a standard 12v backup array already (eg 12v with float charger or similar) you may consider the following:

"SUPERNIGHT™ waterproof DC/DC Converter Regulator 12V Step UP to 24V 72W 3A NEW"

I have not personally used it but a local ham is using it to power a setup where he takes 12v from the onboard PSU or battery)and upconverts to 24v for the switch/poe to feed through.

Claims it is spot on at 24v output.... Again haven't used it myself, but if you have a 12v BBU design in place that could work too.

kj6dzb's picture
Ive been pondering this to
Ive been pondering this to and here are my thoughts...

How to run backup power for a hub.

1. Run it all on a 120acv ups and when the power goes down it switches over. Down side, this its not going to last for ever. I do this at home. 

2. Run it all on a 12v battery with a solar charger, and its all off the grid. Wb6tae has write a web interface that runs on a RPI, the controller monitors the solar charge and battery drain. Works like a charm. This has worked for over 2 years now!  I think the down side is that the nodes dont have 24v.  (photo attatched)

3. So the other day I found It will run a 12v panel and battery, instead of taking power from the 12v side, its suppled at 220acv for a regular power brick. I can plug my switch in too. I also get a 5v for a rpi. 

I favor the off the grid approach. I would rather run the node at 24v. I do very much so like, monitoring the charge/discharge info.

73 Mathison


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If you want 24v for the node
If you want 24v for the node (from a 12v battery) this can easily and cheaply be done with a DC-DC switching supply (aka a boost power supply).

Also careful at the 24v mark, there is a zener inside the node, if your at distance where 12v would work and your running it at 24v its much wiser to back your output down a bit (another advantage of some DC-DC supplies is that they could be adjusted to a more comfortable voltage,  I did this on a site where I wanted to run 22-23v instead of the full 24 because it was only a 80 foot run of CAT5)

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