An HDMI cable, by design, does not transmit conventional electricity or the levels of power that the appliances in your house or the electronic items you use regularly require. That is primarily the reason HDMI cables are not used to power most electrical devices.
That said, HDMI cables are not entirely devoid of electricity. And the minimal electric energy they convey can help power some devices without a dedicated power supply for the particular device.
What amount of voltage does HDMI supply? And what are the devices HDMI can power on its own? Continue reading as we uncover all that’s there to the HDMI and its power supply.
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What Voltage Does HDMI Run At?
HDMI runs at a maximum voltage of 5 volts or has a 5V line. The minimal voltage helps the cable power devices with light or minimal current load.
5V at 250 milliamps is barely sufficient for charging a phone. And with modern smartphones charging at speeds of 30W, 65W, and even 120W, HDMI is not going to charge phones or portable computers anytime soon.
Specific HDMI cables could carry less than five volts of power. Also, there are reported instances of some HDMI cables running more power than 5V. Here is a video showcasing that:
How Strong is 5V?
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The maximum five volts of energy that your HDMI cable carries is not “strong” in every sense of the word.
In other words, you are pretty much sure not to get electrocuted by an HDMI cable or port. A voltage of at least 30V must exist to induce discernible electric shocks.
But please do not go about licking on your HDMI cables, as some weird people on the Internet do. You are likely not to feel an electric shock doing that, but you might feel a bit of a live current tingle.
Can an HDMI Cable Power a Monitor?
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An HDMI cable cannot carry enough power to charge a phone. It’s, therefore, pretty evident that you cannot use it to power a monitor, which has a much higher power requirement.
The maximum 5V current that the cable carries is not sufficient power for any display-bearing device. A monitor, therefore, always requires its power supply.
Similarly, gaming consoles, DVD players, cable/satellite boxes, etc., also require their dedicated power supply. However, a streaming stick can be powered using HDMI.
If you’ve used a Chromecast or any streaming stick before, you should know the HDMI connector that goes into your television’s HDMI port powers, as well as transmits data.
Can a High-Volt, Parallel-Running Cable Induce Current in an HDMI Cable?
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A high voltage cable running parallel to your HDMI cable will not transfer the current from the more powerful cord to your low-voltage HDMI line. If it does, there could be an issue with the device connected to the cable.
The level of voltage that your high-volt cable induces in your HDMI cable is contingent on the current flowing in the former and the magnetic field generated by the high-voltage cord.
But because the power cable has both hot (initial power feed) and neutral (concluding power feed) lines, which carry an equivalent amount of power in opposite directions, the magnetic field gets canceled out eventually.
A magnetic field could exist in certain rare cases where there are minute discrepancies between the hot and neutral current flow. But it won’t be anywhere enough to transfer current to the HDMI cord.
However, to be on the safer side and because it’s easy not to run an HDMI cable alongside a higher current line, it’s recommended not to let your HDMI cable touch or crisscross the high-voltage cable. The two cables crossing paths at a 90-degree angle, however, is okay, if not avoidable.
FAQs
1. Can active HDMI cables power ancillary devices?
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HDMI cables can be broadly categorized as active and passive. The passive cable is commonly used to hook up laptops to external monitors, projectors, etc. These cables have no separate power supply and draw power from the devices they’re connected to.
However, an active HDMI cable has an electronic circuit, which helps boost the cable’s performance. It doesn’t rely on or cannot function on the 5V power that HDMI connectors provide. While these cables come in handy with expansive setups enabled by HDMI, they too do not possess the electrical energy needed to power connected devices.
2. What is HDMI Cable Power?
HDMI Cable Power is an HDMI 2.1 feature that lets the HDMI connector directly power HDMI cables and not depend on a discrete power cable.
The feature renders using active HDMI cords as straightforward as employing passive HDMI cables. However, you’ll need an HDMI cable and an HDMI source that supports HDMI Cable Power to benefit from the feature.
The correct tools ensure the active cable draws necessary power from the connector for safely powering its internal electrical system. You must affix a separate power connection if the source device doesn’t support Cable Power.
HDMI Cable Power draws a maximum of 300 mA from a 5V source supply. It, too, cannot supply power to devices.
3. What is HDMI MHL? What is Its Power-Transferring Capability Like?
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HDMI MHL (Mobile High-Definition Link) is a port that allows you to connect a phone, tablet computer, or other portable devices to high-definition television, an audio receiver, video projector, etc. It employs a special MHL-supported adapter or HDMI input.
The MHL technology lets 5 volts of electric energy pass via an HDMI connector, similar to regular HDMI. However, unlike conventional HDMI, MHL charges the device it connects to while transmitting HD audio and video. Standard HDMI doesn’t come with device-charging capabilities.
When connected to tools that require a lot more than 5V of power for charging, such as a DVD player, the HDMI MHL port will purely function as your standard HDMI port.
There are different MHL standards – such as MHL 1.0, MHL 2.0, MHL 3.0, and Super MHL – and the current ratings could vary across them.
Conclusion
HDMI is excellent at transmitting audio and video digital signals simultaneously and is pretty much de facto in that department. What it is not capable of, however, is supplying power to traditional electronics.
If anyone tells you otherwise and manages to sell you an HDMI cord, you’ve got only yourselves to blame. If you weren’t aware or aren’t cable-savvy, you at least know now.
Catherine Tramell has been covering technology as a freelance writer for over a decade. She has been writing for Pointer Clicker for over a year, further expanding her expertise as a tech columnist. Catherine likes spending time with her family and friends and her pastimes are reading books and news articles.