You are here

Anybody have a favorite POE injector for nominal 12v systems?

8 posts / 0 new
Last post
WL7COO's picture
Anybody have a favorite POE injector for nominal 12v systems?

Similar situations,
1.) Solar w/battery sourced DC
2.) Vehicle supplied 12v or any other power supplied via emergency 12v battery source. 

The more expensive regulated ones have what might be a distinct advantage of being able to connect two separate 12v sources, this may be worth the additional cost in some circumstances, i.e. when you do have two separate DC power sources between 9 and 36 volts.  The wide range of input voltages migt keep radios working  when  power via a low voltage cut off might otherwise shut down the radio at the expense of battery longevity.

The primary question is, do the Ubiquiti radios need a specifically regulated voltage so long as it stays above the published minimum of 10.5v at the radio regardless of POE cable length?  Will the link performance suffer at 10.5 volts vs 12 - 24v?

BTW is anyone LifePo4 batteries vs agm/gel or traditional deep cycle wet lead acid on non AC powered systems?

...dan wl7coo

W2TTT's picture
POE Injector

Try these...we use them all the time for 12-12VDC situations.   There is no reason why they couldn't be used at 24VDC.

You can use any of those batteries to power nodes.  
Gordon Beattie, W2TTT

12V to 24V converter


Flexible shielded cat5 for field use has more resistance than Ubiquiti ToughCable which I found be to stiff for portable use. My wired PTZ IP camera needed 24V to work properly at 150' of flexible shielded cat5.
My solution to generating 24V in a 12V portable world was to use an inexpensive buck-boost converter listed on amazon.
The 24V was converted back to 12V at the camera with a TP-Link extractor with its 5-9-12V switch set to 12V.

Dave Carstensen KM6FQ

WL7COO's picture
Thanks everyone for sharing a variety of solutions.

I'm just about ready to begin testing a NanoStation on a 10' or 18'  push up MFJ Mast powered by a pair of 10 watt 'solar wings' (from Hardened Power Systems) and a 3 amp  prototype LifePo4 mast mounted charger (also from Hardened Power Systems)  charging a pair of  SLA2 9AH batteries hung off the mast.   In a 'no load' situation this combination has performed as expected for a couple of weeks with no draw down load.

I'm hoping this will suffice to keep any NanoStation running all day and all night even through a couple of low light days.  
If the SLAs wont do it,  the same form factor 10 to 14 AH LifePO4s might.

I now believe that while a standard pwm lead acid or agm charger won't safely charge LifePo4 batteries the opposite is both safe and practical, a LifePo4 charger protocol (more complex than simply a 4 stage charger,  I don't yet fully comprehend this protocol) does safely work on SLA & AGM chemistry.

I'm hoping I'll eventually be able to test a few (2 or 3?)  basic types of passive POE injectors sharing the results here.

I'm expecting to discover that they may all work well enough given the almost unbelievable ability of these radios to keep functioning down to 10.4V and their max .5 amp requirement at a nominal 12v and a process to adjust the size the solar power and storage capacity.

...dan wl7coo

ag6if's picture
POE board and 3d printed box.

I have been using a few of these, 4 ports, 12 or 24, coaxial input, and screw terminals, to which I add power pole connection...then I 3d print a little box that fits perfectly.
Jim  ag6if

k1ky's picture
How about a UBNT Power injector?

I've been toying with the idea of performing "surgery" on a standard Ubiquiti POE injector. We've already been successful with replacing the connector jacks in these units.  Shouldn't take much to solder in a "pigtail" with a fuse and a PowerPole connector on the end - should make for a cheap and easy modification.  You could then use it for battery power or AC power when available.  The possibilities are endless!

wa2ise's picture
It would depend on the

It would depend on the resistance of the wire, and the amount of current the load demands.  Of course, longer lengths of the ethernet wire will have more resistance and thus voltage drop for the same current. 

Anybody have a favorite POE injector for nominal 12v systems?

These have proved to be very reliable in off grid WISP service (TP-DCDC-1224) 9-36VDC IN, 24VDC OUT 19W DC TO DC CONV / POE INS

73 de Mick

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer