USB Power Explained (USB Power for Dummies!)

USB power can be really confusing! We explain the different types of USB Power, the level of power each USB type supports, and why the USB cable you use makes a difference. We also explain useful terminology so you know what to look for.

0:00 - Intro
0:50 - Terminology
2:13 - USB-A types
4:05 - USB-C
4:42 - USB-C PD explained
5:49 - Camera compatibility
6:44 - Determining charger type
8:38 - USB-C Cables
9:31 - Computers as chargers
10:57 - AC vs. USB chargers
11:39 - The wrap

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[PANAFRAZER]

-Full Disclosure- Panasonic Employee here...

I wanted to chime in and give some information on the Lumix cameras that support USB-PD, they are the S1, S1R, S1H and GH5M2. These devices can be continuously powered via the USB port and trickle charge the battery at the same time but require the use of a PD device that delivers 9V/3A (27W) for continuous power (battery must be in the camera too). Please refer to your charger/powerbank specifications to determine if this exact wattage is supported.

What if your don't use this PD specification? Not a problem, you can still charge the battery via the port (even with USB A 1.0 spec) but the charging will be slower and you will not be able to power the camera continuously over USB.

What if my USB-PD charger supports higher wattage output but I do not see 9V/3A supported... unfortunately you will not be able to continuously power your device and the charger will default to highest safe supported Voltage/Amperage (most likely 5V/3A) so charging will be fairly quick but again no constant power.

Great topic BTW Chris!!!

[AxelWolstenholme]

Hey guys not to confuse further but theres a mistake at 2:05 where you say it can charge the camera battery 5.8 times, the milliamps is rated at 3.7v on the power bank and 7.4v on the camera battery, you multiply the voltage by the milliamp to get the actual capacity of the battery (Wh) watt hours, so the watt hours on the camera battery is 12.8 Wh and the power bank is 37Wh so you would get upto 2.8x charges from the power bank (it would be roughly 10 - 20% less due to power lost in conversion)

[niccollsvideo]

We appreciate the corrections on the capacity of batteries, and losses of energy whilst converting. Thanks to everyone for helping to clarify this situation!

[yeungns]

Love DPR for also giving us contents that are not related to any brands or products. Very useful and clear explanation. Great job Chris and Jordan!

[timlaunyc]

USB PD spec was updated this year to 3.1 (not the USB data protocol), increasing the power limit to 240W. It keeps the same 5A current limit, but added 28V, 36V and 48V as part of the spec.

[dtibor]

Sorry to be picky, but the olympus battery works at 7.4V (2 cells in series) and by the power bank works at 3.7V. In this case you can charge only 2.9 olympus batteries from that power bank, but in practice you will get around 2-2.5 full charges due to losses.

[miguellee]

Not going to lie, this is the first video I’ve ever watched where these protocols are explained so thoroughly and dumbed down for me! 😂

[MarksUkuleleTips]

Great video. Yes, a video explaining the I/O data protocols and transfer speeds would be of great interest.

[GoodGuysMedia]

This was a great installment! I had to do all this research to demystify my confusion. But all of your info was spot on (as always)! I'd be interested in a video on transfer rates and the various types of USB cables and adapters available to achieve maximum data transfer speeds. I'm still tackling that one myself

[matthieuzglurg]

just a little note : that's not "milliamp per hour" but milli amp hour, and that's a huge difference. milliamp hours is basically milliamps times hours ([A].[s]) while milliamp per hour is the rate of current per hour ([A]/[s])

milliamp per hour is a rate of discharge, milliamp hour is a capacity of charges (for reference : Amperes (Amp) are coulombs per second, basically the number of charges that goes through an electrical wire every 1 second). So, if you have milliamp hours, that's basically ([C]/[s]).[s] = [C]. Coulombs being the number of charges, milliamp hours really are a unit of charge capacity)

On the battery there's also a Wh rating, and that's the same kind of deal. That's not Watts per hour, but Watt hour. A Watt can be found with the current and voltage going on a wire at time T. But a Watt can also be a unit of energy, since a 1 Watt = 1 J/s. A J is a unit of energy, and 1 Coulomb (an electric charge) has a value of 1C = 1.6e-19 J, so you can land on your feet afterwards converting mAh into Wh (you need to take in account the voltage of the battery, especially if you want to compare the capacity of two different batteries operating at two different voltages. That's why we generally prefer the Wh rating because it is independant of the rated voltage of the battery)

(yeah I know that's a bit long and complicated for a "little note" but hey, I'm a measurements physicist, that's literally my job to be picky about units !)

[francisresch]

Thanks once again for a very informative and well organized video. You guys do an outstanding job. YES please do a video or series of videos outlining the broader functions of USB interfaces. It’s a subject that needs to be addressed and I’m sure that you two would do your typical thorough job.

[gileselliott]

Thank you for this. Clear explanation that I have searched for and not found anywhere else.

[danbuchman]

Thanks for explaining this issue. I’m not an electrical engineer and never took the time to learn everything you explained today. It really cleared it up for me.
I’m not sure if you have done a deep dive on storage solutions in the past, but would definitely enjoy a similar video on that topic. Everything from SSD hard drives, difference between SD & CF, RAID, and even cloud storage would be interesting. Love the content. Would have really enjoyed more of the watching the camera charge as well. How long can Chris sit still???

[HBProductions.]

Love this video! I'm not a professional photographer though, just an electronics repair and repurpose enthusiast/hobbyist and this info came in extremely useful to know how to setup electronic diagrams for power consumption/delivery for DIY projects to make custom hubs for muti device use. Thank you very much!

[andreverville]

Great video, thanks! Since a few years, I only use USB chargers that have a digital display showing the amperage out. This is often the only way of knowing what is really happening and if the charging really gets done. They cost more but are worth it.

[MichaelSeneschal]

I love this kind of stuff. It’s important. Thanks for making this. I remember FStoppers made a video about their charging station and how they have it set up… super interesting. You’d think it would be boring, but we all deal with this (charging, etc.) so it’s all a common interest.

[PaulBawby]

Very well explained, I learned some very useful things about USB-C and PD.
Thanks for sharing!!

[peternavanac]

Wow, that was super helpful. Love your channel, content and the professionalism with which you deliver your content.

[ShaneTheGeek]

While I already know all this working in the IT field it’s nice to see a concise and easily digestible video that breaks it all down for the laymen.

[geraffe]

Thanks Chris. Very useful video and kudos for starting to tackle a subject that others haven’t. Look forward to subsequent one regarding cables and data transmission