3 Ways to Power Devices with PoE: Wall Plug, Multi-port Injectors, and Injector/Splitter Cables

I regularly browse new arrivals feeds of popular websites to look out for interesting products, and I’ve noticed Banggood has several inexpensive PoE plugs and injectors going for around $6, which is quite cheaper than I would have expected.

Apart from MatchX LoRaWAN gateway, I’ve never really used PoE to power devices, but I may soon have another look on Raspberry Pi 4 board with a third-party PoE HAT. PoE is mostly interesting if you need to run long cables to your boards or IP cameras since using a single Ethernet cable for data and power saves on cabling.

24V/48V PoE Plugs for the European market

Cheap EU PoE PlugBanggood had three PoE plugs with prongs made for the European market:

  • 48V/0.5A (24W) PoE Wall Plug
  • 12V/1A (12W) PoE Wall Plug
  • 24V/1A (24W) POE Wall Plug

All three plugs are visually identical with a LAN port to connect to your router, and a PoE port adding power to the data signal, and only differ in terms of voltage and power. The one you’d select will depend on your target device specifications, and for example, the official Raspberry Pi PoE HAT supports a 37V to 57V input range, so the 48V/0.5A PoE wall plug should be suitable.

All three models go for the same $6.25 including shipping for orders over $49.99.

4-Port PoE Injector

4-port poe injector

If you plan to power more than one device over PoE, they also got you covered with a 4-port PoE Injector supporting the 802.11af standard. The device comes with 4 Ethernet (RJ45) ports to be connected to your router/switch, a 2-pin terminal block and 5.5/2.1mm jack to which you can connect your own power supply with voltage ranging from 9 to 48V, and 4 PoE ports than combine data and power to feed into your IP cameras or boards.

802.11af PoE Injector

The PoE injector sells for $5.76 including free shipping and is more flexible than the other solution since you have to bring your own power supply.

PoE Injector & Splitter Cables

PoE Injector Cable

Another way to power any devices with PoE it is by using an injector cable as shown above together with a splitter cable. The injector cable is connected to your router, and a power supply (5V, 12V, 24V, or 48V supported), then you run your long Ethernet cable between the injector and splitter cables, and connect the latter’s Ethernet and 5.5/2.1mm power jack to your target board or device.

This is by far the cheapest method since you don’t need to acquire PoE compatible hardware. For example, by adding a 5.5/2.1mm to micro USB adapter, you could power your Raspberry Pi 3 Model B+ over PoE without having to spend $20 on the PoE HAT. The injector and splitter cables set only costs $3.38.

Now Banggood does not have the exclusivity on such PoE accessories, and you’ll find interesting options on eBay and Aliexpress as well, even as low as $1 per cables sets if you purchase in small quantities.

What I’m less clear about are safety issues especially for the wall plugs since I don’t see any UL marking, reliability, and potential compatibility challenges of such accessories. Feel free to comment if you have experience with PoE.

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TofJean-Luc Aufranc (CNXSoft)Tadej BrunsekvtominXtract Recent comment authors
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Da Xue
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Da Xue

The stuff you find on most Chinese sites are using the cheapest designs possible. They are giant safety hazards waiting to happen and do not come with any liability to the seller.

Mandatory fuses to prevent short circuit fires are almost always non-existent. If you value your house not burning down, get name brand stuff.

That is not to say the name brand stuff is that much more costly to make. It is the nature of the beast.

Failure mode is important design consideration and it is an afterthought for cheap products.

MAHMOD
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MAHMOD

adding fuse is maybe 2-3 minutes job, if you can do it yourself this still of great value, if not then just go with the commercially certified devices

Xtract
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Xtract

What about POE switches? Shouldn’t they be option 1? 😉

eFfeM
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eFfeM

The last part of this “All three models go for the same $6.25 including shipping for orders over $49.99.” is probably not correct.
If I follow the link, I can order this with free (standard) shipping to NL for $6.25 .
No mentioning of a minimum order (and I never had a minimum order quantity with banggood for other items)

vtomin
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vtomin

Does anyone know where I can find a cheap switch with PoE INPUT (a PoE powered switch)?

I need to extend the range of a LAN cable that would be longer than 120m but I don’t have a power supply in the middle. I don’t need PoE passthrough, just input on one port.

Or, perhaps, one of these splitters could be used in reverse with an ordinary switch? Has anyone tried that?

BTW, there are cheaper splitters on Gearbest.

Xtract
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Xtract

Cat6 cable maximum recommended length is 100m.

The splitters work in both directions (check the picture), but make sure the injected POE voltage is the switch one.

vtomin
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vtomin

I know that it should not exceed 100m. This would be maybe 65+65m.

The voltage is exactly what’s worrying me. If it’s less than 12V then will it work on this distance (65m)? If not, I would have to find a switch that works with 12V.

But the best would be a switch with PoE IN. I just need to find a cheap one.

vtomin
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vtomin

I found one on AliExpress for € 5.34 + shipping € 3.50. There is also a waterproof version but it’s € 57.42 + 3.78.

Tadej Brunsek
Guest

There is also another equipment in 4 port PoE powered switch sector. Those are 4 port poe powered and 1 port uplink. So you do not need wires for every individual camera to the router: https://www.banggood.com/ESCAM-42Channel-Fast-Ethernet-POE-Switch-for-Network-Switch-IP-Cameras-p-933396.html

Tadej Brunsek
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Tof
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Tof

I’ve checked some pictures posted by buyers in their comments on Aliexpress, for some POE injectors, plugs and splitters. As some buyers have opened them to check internal components. And frankly while I was tempted by the price, I wouldn’t trust these cheap devices for powering my equipments 24h/day unattended…