How To‎ > ‎


OK, you've got your uplink, and you've got it elevated above the Playa and pointed at Center Camp.  Now, how are you going to power the whole thing?

Ubiquiti gear uses Power-over-Ethernet (PoE), which delivers power to remote equipment (at the top of a pole, for example) over the same Ethernet cable that carries the data, using wires that are unused for data.  You need to beware that there are two different INCOMPATIBLE forms of PoE, and if you use the wrong kind, YOU CAN DESTROY YOUR EQUIPMENT!  

First, there is "standards-based PoE" (based on the IEEE 802.3af and 802.3at standards), which delivers 48V DC; this is what you see from most "PoE-capable" Ethernet switches, used to power Voice-over-IP (VoIP) phones and such in office environments.  IF YOU CONNECT UBIQUITI EQUIPMENT TO STANDARDS-BASED (IEEE 802.3af or 802.3at) POWER WITHOUT AN ADAPTER, YOU WILL FRY THE UBIQUITI EQUIPMENT.

This is because the Ubiquiti equipment, and much other cheap WiFi gear, uses so-called "passive PoE", at lower voltages.  Ubiquiti equipment will work on anything from 12V to 24V DC (some of it will work as low as 6V, depending on the model, but the upper limit is 24V for all Ubiquiti models).  In order to use Ubiquiti equipment with "standards-based PoE" (IEEE 802.3af or 802.3at), you need to use a $20 Ubiquiti Instant 802.3af adapter.

One way to provide PoE to a piece of equipment is to connect the equipment to a PoE-capable switch; however, as noted above, most of these switches (but not all, see below) are 802.3af based, and Ubiquiti equipment can't be connected to them without using an extra $20 adapter for each piece of equipment.

Another way to provide PoE to a piece of equipment is to connect a so-called "PoE injector" to the Ethernet cable.  The PoE injector has 2 jacks on the "input" side (one for Ethernet, and one for power), and one on the "output" side (combined Ethernet + PoE).  Most Ubiquti gear includes PoE injectors with standard AC "wall wart" adapters that take in 110V AC and put out either 15V DC or 24V DC, which is within the 12-24V DC range that Ubiquiti equipment needs. 

By the way, keep in mind that with PoE, you lose about 3V per 100 feet of Ethernet cable between the PoE source and the equipment; so, if you use a standard Ubiquiti 15V DC PoE injector, and a 100-foot Ethernet cable to your equipment, then your equipment will see about 12V DC.

If you have multiple pieces of PoE-powered equipment, and you're using PoE injectors rather than a PoE-capable switch, then you need a separate PoE injector for each piece of PoE-powered equipment.  This can turn into a rat's nest of wiring really quickly.  It would be better to use a PoE-capable switch, but unfortunately (as explained above), most PoE-capable switchs put out "IEEE 802.3af standard" PoE, which is 48V DC, and which will fry your Ubiquiti gear (unless you're using the $20 Ubiquiti Instant 802.3af adapters for each piece of gear). 

Fortunately, there is a solution...  Tycon Power makes a 5-port Ethernet switch, model number TP-SW5G-NC, that is perfect for this situation.  This switch has 5 Ethernet ports, and a DC power input that will take anywhere from 12V to 56V DC.  The input voltage is passed along as-is to PoE on 4 of the 5 Ethernet ports (the 5th port does not have PoE, and is for connecting non-PoE devices such as a laptop or another non-PoE switch). So, the solution is to get one of these switches, feed 18V or so of power to it, and connect all your Ubiquiti gear to it; voila, no need for the rat's nest of separate PoE injectors, or for the extra $20 Ubiquiti "Instant 802.3af" adapter for each piece of equipment.  This switch is a little pricy (about $140, versus maybe $30 for a "typical" Linksys 5-port Ethernet switch), but it saves you from the rat's nest of PoE injectors, which makes everything more reliable.  (By the way, if you buy one of these switches, MAKE SURE YOU GET THE "-NC" PART NUMBER!  Tycon makes other versions of this same switch that put out specific voltages.)

The Tycon Power TP-SW5G-NC switch does NOT include a power supply, so you'll need to supply your own that is big enough to power all your equipment, and puts out the appropriate DC voltage (15-18V DC is about right).  You need something that is big enough to power all the PoE-powered devices, plus the switch itself.  You need to find out the amperage (A) requirements of all your devices, add them out, and then use a power supply that is comfortably larger than that (at least 2x, say).  Power requirements are typically expressed in watts, but you want to add up amps; to convert from watts to amps, you divide by volts (for DC, watts = volts * amps, so amps = watts / volts).

If you do the research, you find that

  • a NanoBridge M5 has a max power consumption of 5.5 W; at 15V DC, that's about .37 A (= 5.5 W / 15V)
  • a Bullet M2HP (which you might be using as your LAN WiFi AP; see Distribution) has a max power consumption of 7 W; so 7W / 15V = .46 A
  • the Tycon TP-SW5G-NC Ethernet switch itself has a max power consumption of 5 W, so 5 W / 15V = .33 A
That's a total power requirement of 1.16 A (= .37 A + .46 A + .33 A).  So, you need a power supply that can provide comfortably more than 1.16A at 15V DC.  

You want a regulated power supply, so that the voltage is stable at 15V regardless of the actual amperage being drawn at the moment (unregulated power supplies only provide their "specified" voltage at a particular amperage draw).

As it happens, a laptop power supply for an old Toshiba "Satellite", "Portege", or "Tecra" laptop takes 110V AC in and produces up to 5A at 15V DC (regulated) out, which is just about perfect, and is available new for less than $10 (  Buy one of those, clip the plug off the laptop end of the wire, wire it to the input power of the Tycon PoE switch, plug the other end into an AC power source, and you're in business.

Oh yeah, an AC power source...  On the Playa, that means a generator, and your WiFi installation is only going to be as reliable as your generator, which usually means "not very"...  If it's OK for your WiFi to go down whenever the generator breaks down, or is shut down for fueling or service, then just plug the power supply into the generator and you're done.

If you want your WiFi installation to keep working even when the generator doesn't, the solution is to add a uninterruptible power supply (UPS) of some sort to the mix.  Many camps use regular commercial UPS systems that you can get at CostCo or any office supply store; beware, however, that some of these UPS systems (especially the more expensive ones, ironically) get really unhappy with the "dirty" power (voltage sags/swells, frequency surges/lags, etc.) that comes from many generators, and may refuse to charge from the generator...

A UPS basically consists of a power supply, battery, and charge controller.  If you want to build your own, you've already got the power supply (the same one you're using to power your PoE Ethernet switch).  For the battery, you can buy a 12V 18AH (amp hour) battery for about $35 (for instance, a Triumph TR18-12 from  This will power your WiFi installation for several hours, even if the generator breaks down, or is shut down for fueling or service.

You need a "charge controller" to sit between the battery and the DC power source (the laptop power supply described above, plugged into the generator), to keep the battery charged but not over-charged.  There are charge controllers designed to work with solar panels, which are a good fit for this situation.  There are two kinds: ones with 2 connections (for power source and battery; you connect the load directly to the battery), and ones with 3 connections (for power source, battery, and load).  You want the kind with 3 connections, because if the input power stays off for too long, it will shut down the load before completely draining your battery, which protects your battery and makes it last significantly longer.  I use a Kintrex SPC0601 7 Amp Solar Power Charge Controller ($16 from Amazon:; these are no longer available, but you shouldn't have any trouble finding something similar).

Finally, you need something to keep all this gear (switch, power supply, battery, and charge controller) out of the sun, wind, dust, and maybe rain.  I'm fond of using Rubbermaid tubs, with little slots/notches for cables cut into the rims of the tub such that the notches are covered and protected by the lid when the lid is on; I then use a bungee cord to make sure the lid stays on.


On a previous incarnation of this page (hosted elsewhere), various folks had contributed useful observations:

  • With respect to the no-longer-available Kintrex SPC0601 solar power charge controller, Aaron Muszalski said: 
  • Phil Sadow said:
    • Don't bother with a charge controller if doing solar. Use a standard lead-acid deep cycle battery (not gel or AGM) and all that will happen is it will (possibly) lose a tiny amount of water over 2 weeks. Not even enough to notice. When you get off-playa, add distilled water and recharge fully.
    • If you are charging from a genny, simply use a RV style DC converter. They will put out about 14 volts to charge your battery and power your loads. A cheap battery charger will also work as long as it has at least 15 amps, so it can recharge the battery in a reasonable amount of time. Avoid the "smart" battery chargers, as most require button pressing when power returns and the playa kills them fast.