If you own a PoE-enabled network system with multiple devices, you may have already wondered if you can power other devices like laptops across this technology. While PoE has allowed for many network-enabled devices to draw power through a single cable, a power-hungry device like a laptop may be more difficult.
For most PoE systems, you won’t have the required maximum power rating to support a device like a laptop. Most laptops need about 50 watts to operate, while most PoE systems can support a max of 15-30 watts.
PoE was designed to support devices that require little power, like security cameras and telephones. A laptop needs more power than this to operate correctly. While computers are being introduced to the market with PoE support, most laptop designers aren’t going to include this feature any time soon.
PoE stands for Power Over Ethernet and is a great tool to use when setting up multiple devices over a network. What PoE provides is an all-in-one solution for cabling. PoE cables such as the ZOSI Cat53 (on Amazon), use the Cat5/Cat6 ethernet standard to transfer both data and power.
Two of the four paired copper wires inside the ethernet cable are used to create a loop for power to run on. This means PoE enabled devices connected to this network will not need an external power source to operate. PoE saves time on installation and can also limit the costs of pulling multiple wires. PoE can support all kinds of devices including security cameras (IP Cameras), alarm systems, PoE switches, wireless access points, and VOIP telephones.
PoE Type 1 is based on the IEEE 802.3af standard and can support a maximum power of 15.4 watts. In recent years we have seen upgrades to this standard with PoE Plus Type 2 aiming to support devices with higher power needs, up to 30 watts. As technology progresses, so do the power needs of systems. This is why there have been developments of even more advanced PoE standards.
PoE++, known as Type 3, is the latest to be developed and can support devices that need up to 60 watts. This standard uses all four of the ethernet cable’s paired wires to provide power. This technology is still being introduced to the market and currently has limited applications. You may have already seen some PoE++ devices around.
One of the most widely used commercial application is setting up slim clients, or barebones computers, running point of sale systems in restaurants and other retail establishments. These devices only rely on the single PoE connection to power the system and transfer data over a network.
It's important to note that PoE plus and PoE++ are not meant to replace the IEEE 802.3af standard completely but instead meant to work for devices that require a lower power source. PoE systems are easy to set up, cost-efficient, good when pulling cables to hard-to-reach places, and they also provide robust network security. There are limitations when using PoE, however, especially when working with devices that require more power.
When it comes to trying to power a laptop over PoE, you are going to have issues. This has to do with the kind of power a laptop needs to operate and the kind of power that a PoE system can provide. The problem is that most consumer laptops aren’t designed to work with PoE. There are computers that can be run on PoE, but they have built-in power limitations and run on the higher PoE standards.
While higher PoE power standards support increased wattage, most systems you see today are usually based on PoE Type 1, with some exceptions for PoE plus. The systems that use the higher standards, Type 3, are typically fitted for specialized equipment. For most of us, our PoE hardware just doesn’t have the type of power needed to support a device like a laptop.
To explore this further, we need to have a basic understanding of amps and watts that these devices will use. We already know that your standard IEEE 802.3af standard will be 15.4-watts, much lower than 50+ watts needed to power a laptop. The PoE standard also does not support the required amp rating for a laptop. PoE standard supports up to .35 amps, while your everyday laptop needs around .5 amps.
On top of all this, most modern laptops either don’t include an ethernet port and many of them will not support PoE even if they do have an ethernet port. While you may find a workaround for this omission, you will still not have the necessary power to operate your device.
If you're working with a higher PoE standard, like PoE+, you might have a more feasible scenario but still will have a lot of issues trying to get these two devices to work with each other. At the end of the day, PoE is not intended to power your laptop; there is no built-in compatibility with these technologies.
While powering a laptop with PoE may be difficult, if not impossible, you may be wondering if your laptop can provide the power you need for your other devices. You may run into the same issues as above, mainly the connections you are using. It is also worth noting that laptop designers are very aware of the power usage of the device. Laptops are intended to be portable and rely on their power management to control battery usage.
For some laptops, this even means you can't charge power-hungry 12-watt devices like a phone or tablet properly through their USB ports, let alone connecting something that needs constant power like an IP camera. While you might be able to plug in an ethernet cable into your laptop and get a camera working, the fact of the matter is you are going to be draining your battery faster. You can kill your entire charge in a matter of minutes.
A laptop is not intended to be a hub or a switch, but it can still be used as one in a pinch. If you are still curious about using PoE equipment with your laptop, you may want to invest in a good PoE Power Injector (on Amazon). These devices will power the device with a standalone AC adapter, which frees up the power from your laptop.
While they are great for situations where power is an issue, they can be cumbersome when using more than one. There are some power limitations for PoE. New standards are being developed which are geared towards operating more power-intensive products, but most systems you will see today can’t power much more than an IP camera.