-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!!!
Very good information and Pany users will appreciate it so much. But as a Sony user I feel so pissed that they didn't mention about any sony cameras in the video while the whole video was recorded on a sony camera! How the hell should I know how my cameras will act in similar situations? Maybe a Sony employee is also needed here while DPreviewTV doesn't give a s*** about any other brands users than the canikon.
I don't think it's necessary to go down the well trodden path of biased, brandist accusations on our part. We simply didn't mention Sony because firstly we don't want to get into every single possible permutation of camera and powerbank compatibility, and secondly because Sony cameras are very flexible and we've never really had an issue charging them. Although I believe the latest Sony cameras are PD compatible, they don't require PD chargers to charge the batteries. The only real issue we ran into so far was Canon, so we used them as our example.
@@niccollsvideo Thank you for the enlightment and information. I didn't mean that anyway. Just got pissed and felt I'm watching a video from a decade ago when we Sony Alpha users been ignored in most of the photography contents. Honestly I get surprised whenever I watch an old review of a Sony A-mount camera on RUclips and feel the dominance of Canon and Nikon was making most of reviewers going harsh on Sony cameras novelty in models like A77 and A99 with their best of all times rear screen mechanism and many other slt models and features.
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)
THIS ^^^^ Is crucial that this is clarified in the video, because even the manufactures of powerbanks use examples of how many times a certain battery can charge a certain phone. For example, Anker may say that its 10.000mAh powerbank can recharge an iPhone 12 just 2.5 times (just an example); if you do the math, it will never add up, and that's just because of the power lost in the conversion due to the output through the USB port.
Exactly! It's very sloppy to mislead viewers by implying Ah would equate capacity. It's like the whole "this tiny camera is 25-300 mm f/3.5" nonsens all over again. DPReview has learned equivalence of optics, and now needs to learn the equivalence of power.
@@LuizAlejo No, it's not the losses from conversion, but the actual capacity difference. The Ah of different V aren't comparable. Doubling the V will halve the Ah, and vice versa. Losses come then on top of that.
Yup, it's well below 3 charges for that specific battery. There's loss from converting the 3.7V from the batteries in the powerbank to 5V (assuming it's using 5V), then the camera's internal conversion from 5V to 7.4V.
This is true (I was going to post the point myself). Let’s face it, the power bank manufacturers do this to confuse buyers into thinking they’ve got more capacity than reality. Dpreview fell for it… but they wouldn’t be the first!
We appreciate the corrections on the capacity of batteries, and losses of energy whilst converting. Thanks to everyone for helping to clarify this situation!
Did you know you made a mistake on the internet? Don’t worry, six million people that have nothing else to do will make it their sole mission in life to nip at your heels because this mission is more important than the meaning of life. Loved the vid.
@@agenericaccount3935 Correct information is important. It is easy and appreciated to provide an update/correction/whatever in a civil tone that benefits not only the content creator but the viewers.
@@agenericaccount3935 Calm down? What a laugh. You're the one who wrote line after line after line about people who make corrections on the internet. I made no correction, I simply pointed out that there's a polite and civil way to do it. But I'm the one who needs to calm down? OK, guy.
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.
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.
Isn't Apple's power brick the only one that supports it so far? Looking at the size of that thing, despite it using GaN, I worry about the availability and size of PD 3.1 chargers in the future, lol.
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 !)
To be fair, everyone should be picky about units if we want to understand anything at all. Although sometimes you can guess what people mean when they say something stupid like "fast speed" (usually meaning high speed, not high acceleration, which it actually means) or "cheap price" (meaning a low price, which was acquired for free by looking at the sticker on the product). And it's not only related to science. E.g., check out the short discussion Alice has with The White Knight about "A-sitting On A Gate" (a song, which name is called "Haddocks' Eyes").
Thank you so much for using the metric system. It would have got way too complex if you used USA units of BTUs. Hopefully the USA will change over soon to simplify other unit conversions.
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.
Would definitely love to see more videos about data transfer rates, efficacy and adaptability of cables, and all that kind of techno-wizzardry of work arounds and make-do. The current scope of tech is amazing and confusing in equal measure
Very informative 🤔 I wasn’t aware of this complicated mess when it comes to charging. I’m more “in the know” when it comes to data exchange speeds with all these different protocols though.
Good information......small correction.....power banks typically use one LiPo cell at the rated capacity or more in parallel combining to the rated capacity. They are 3.7 volts nominally and are max at 4.2 volts. This voltage is increased by a circuit to the 5.1 volts needed. This can not happen without reducing the rated capacity ( ie 10,000 mAh power bank can not deliver 10,000 mAh at 5.1 Volts) There are powerbanks that deliver higher voltage using a similar arrangement.
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
No, it wasn't spot on, because he doesn't know even the very basics of electrical power. He uses Ah (incorrectly calling it A/h) when he should be using Wh. See other comments above for correct information.
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!
Thank you so much for making a video about this and trying to make it as easy as possible. My brain still hurts anyway... Long live analog photography!
Very useful, after buying several new chargers and cables thinking it will save me time and convenience by giving me super fast charging, now I realized they are not going to do that. PD cables and charger is what I need!!!
This may be an unpopular opinion, but I prefer having the wall charger over USB solutions. USB solutions are always a secondary method of charging convenience for me. While all of the increased wattage is great for the newer USB and Thunderbolt specs, that increased wattage creates excess heat, which, in my experience, is not the best for prolonged use of electronic equipment or batteries. Wall chargers tend to be much better at managing this than USB power options are and, to me, at least, seem safer and more reliable than USB solutions. Furthermore, USB C connectors have this nasty habit of falling out of their ports after extended use! We need a better semi-locking connector especially for power or audio connectivity in our devices. Excellent video, as usual!
I agree. I much prefer wall chargers. I can buy two batteries, charge one at the wall, while using the other. With USB charging, when my battery is dead, I have to plug in the camera, and it's not available to use - unless I buy both a second battery AND a wall charger. I don't see the advantage of USB charging over wall charger. Another point against USB charging, and this may only refer to some cameras, is that it takes a long time. My old Nikon D5100 batteries would charge in 90 minutes in the wall charger. My current camera, a Fujifilm x-s10 takes around 4 hours or more to charge the battery in camera!
You cannot expect 10000mAh battery to charge Olympus battery 5.8 times. You have losses (like thermal) that will significantly lower the number of charges.
10 Ah at 3.7 V is equivalent to 5 Ah at 7.4 V. Actually you should be using Wh instead of Ah. To get the Wh you multiply the Ah by the V. 10 Ah at 3.7 V is 37 Wh.
It's actually worse than that. Amp hours, unless the voltages are the same, cannot be divided like that. If you look at the footage, the bank is labeled 10,000mAh and 37Wh, which is the rating of the 3.7V (nominal) batteries inside, 10000mAh x 3.7V = 37Wh. The camera's battery is rated 7.4V at 1720 mAh, and 7.4V x 1720mAh = 12,728mWh = 12.728 Wh. The bank can charge the battery 2.9 times at most, before losses are considered.
I'm an Emergency Room Psychiatric Clinician, and for years, I've wondered how you guys still roam free. To get back on topic though, things have been such a maddening mess since the Pandemic, and seeing as how these PD chargers are capable of delivering such a stable flow of reliably high current, I was wondering if you or Jordan have any personal knowledge on the off label use of these devices as Electro-Convulsive Shock Therapy Delivery Systems. There is such a profound shortage of Mental Health resources at this point in time, this might be just the ticket. Thank you so much for your brilliant work. You guys keep me relatively sane. =)
The Olympus E-M1 Mark III can be charged by standard as well as PD power banks and it can be run via PD powerbanks. It supports PD powerbanks up to 100W
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.
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???
You learned a new word to substitute other words with and now you don't need to think as much to use the proper words. Just got to bleep or silence them out. Good for you.
Really strange that Nikon and Canon can't implement a "slow charge" mode at 5V, just like Sony and I think Fuji, where a non PD charger can charge the camera - slower, but at least it charges. Which can be a huge difference if you are far out in the world on some job and have forgotten your PD charger or it broke.
After frying one of my favorite Chorus pedals with a 12v power supply (it runs at 9v).... believe me, this is a great reminder that all our glorious tech is worth fuzz all if one doesnt look after it properly, and powering things properly is definitely the most important thing.
Fantastic, Thanks! Maybe touch on these universal camera battery chargers in a future video. I like to charge my removable batteries outside the camera.
Came here looking for answers on what type of USB charging ports would be best to integrate into a "charging" end table for my living room. Everything here was dumbed down to my level of understanding perfectly.
Thunderbolt is a blessing for modern cameras. Power delivery is one thing, but also having the data transfer rate of Thunderbolt for some of these giant raw files and 4k/8k video to work on is the bigger benefit in my workflow. It is nice that my Macbook doubles as a power bank for my camera in an emergency lol.
Great stuff Chris, just purchased the Canon R6 and was having that exact issue. I found that my Samsung S20 charger works to charge the R6, but none of the other hundreds of cables and USB plugs seem to work and know I know why👍😎👍
Thanks. I just got a Samsung Galaxy s22 ultra, capable of 65w charging but I didn't have a charger capable of delivering that amount so I bought one, but reading the label I saw many different outputs and I was confused. And because I wanted to know if I could charge my laptop (45 Watts) and other devices such as my headphones (which I doubt could resist that amount of power) I wasn't sure of what to do. And now thanks to you I got all the answers I needed. Thanks a lot!
Great video, but I think you also need to cover PPS... ideally to fully cover the gamut in pursuit of "one charger to rule them all", it needs to be USB C PD 3.0 PPS compliant, and 65w or greater (such as the Anker powerport lite or Anker Nano II).
Best i didn't know i needed to know video, thank's for sharing guys and yes i would be interested now, to learn more about the different capabilities and transfer protocols of the different cables out there. I'd watch such a video for sure.
When I saw the title of this video I thought it won't be very interesting, how wrong I was. My wife and I recently went to Spain on holiday, we took 3 cameras, so 3 old fashioned wall plug type chargers, we took 3 mobile phones, so 2 more cables and chargers, and a laptop with its own charger, all those chargers took up space and more importantly were heavy. Perhaps I can consolidate them down and use a power bank, unfortunately only one of the cameras supports USB charging, but as I am thinking of getting a new laptop, your advice on a Thunderbolt port will be useful. So, thanks for the video, if you don't watch then you don't learn.
Once again a great resource info package on stuff everyone deals with one way or the other, highly valuable and important details, beautifully done - thanks so much!! One aspect though should have deserved some more attention, and that is the question about whether a powerful charger can possibly hurt a small device, like using a laptop charger that can send 65W on a camera or cell phone that needs only 5W to 20W for example. You briefly mentioned the handshake technology (always reminds me a bit of two fax machines exchanging their noisy spec info while negotiating their fastest common denominator), but I believe a lot of folks would have found it comforting to hear a bit more about what might and what will not hurt our sensitive equipment.
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
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.
Very well done and that complement comes from an Electrical Engineer who spent time designing charger IC for smart phones. It might be nice to add a brief addition for PD vs Quickcharge vs IQ3 chargers and their cross compatibility. Take care.
It's worth mentioning that multi-voltage/amp ratings on the charger can also indicate other standards like Qualcomm's QuickCharge or Mediatek's Pump Express. Those will have USB A ports, though, but will also have 9V and 12V outputs in a lot of cases. That being said, every time I've charged a USB PD device using a type A to type C cable into a brick that only supports QC (QC2.0, in this case) it has triggered the higher voltage/amperage charge modes, and the same when using a QC device with an adapter into a USB-C PD specced charger. Not sure if it's intentional backwards compatibility or what.
This was an excellent and needed video. After watching every cell phone on earth go to usb-c I was shocked that cameras were still stuck in usb-micro (a6400etc) When the zv-10 was released most reviews did not even mention the usb-c port. Transfer rates and charging are so improved it would be excellent if you could educate us more on the new capabilities of the newer cameras with usb-c. Thanks.
This is a very useful video for the layperson. Just wanted to clarify that most power banks advertise mah ratings based on 3.7V nominal, which is NOT typical of devices (usually they are at 5V). So the TRUE mah available is actually considerably less. A good rule of thumb is about 66% of labeled rating. So that 10,000mah power bank will actually peter out after having dished out a total of a little over 6000mah to any devices plugged into it. ;)
@chris, this is a fantastic video. So much of this basic stuff is usually overlooked but is actually critical to successful production especially in the field. You did a great job explaining things without getting too technical. Kudos on that. A correction: you said a 10,000 mAh battery pack can charge a 1720 mAh battery, 5.8x, but your math is based on being able to use all 10,000 mAh. The fact is that you can never get ALL of the 10,000 mAh out of the battery pack- you can never deplete the cells to zero. All cells have a "base" capacity where you simply can't draw any more. Moreover, lithium packs have controller boards that will stop output to protect the cells. The same goes with the battery pack for the camera. It's 1720 mAh, but you'll never drain it to zero. It's almost impossible to know the exact actual "usable" capacity of the battery pack because it's dependent on the type of cells, the number of cells, quality fo the cells, etc, and much easier for the manufacturer to just label with total capacity. Secondly, you noted that all kinds of PD rated gear can be charged by universal PD rated adapters. You say this is more convenient than separate AC battery chargers. I find having a battery on a charger, separate from using my camera in a gimbal, to be far more convenient than trying to power the camera with a wire, or charge it while using it. Your mileage may vary. This is especially relevant for camcorder batteries like the ubiquitous NP-F (Sony Infolithium-L) battery that is used for cameras, lights, monitors, and a lot more these days. A single 7800 mAh NP-F can run gear for hours at a time, while another set of batteries are getting juiced back up in "video village." I find a 5 second battery swap to be the most convenient solution for mobile filming than having my camera tethered to an external power source. Also, as a Panasonic employee noted on the RUclips video- some devices can't charge and run the camera at the same time, or can only trickle charge if the camera is running, and either of those are dependent on the wattage of the power adapter / battery bank, and the capacity / capability of the camera to draw and utilize enough power to do one, or the other, or both. Making t a lot of cross referencing minute, obscure, and sometimes simply unavailable specifications. Again, making the case to charge the batteries externally. This is what works for me. Again, Kudos on a fantastic video about an important, and near universally overlooked topic.
Great job on the video, I've been working on something similar though not nearly as detailed. The Nikon Z5 seems a lot less picky than the Canon M6 Mark II that I have. Those two cameras have gotten me exploring USB-C cables and chargers. Definitely has been a journey, lol. I agree that if you can find the right combination of components it's more convenient and travel friendly than old direct charging adapters.
it's really time we'd find a solution to label our cables. As a full-time traveler constantly updating my gear, it's a real PITB... and finally getting powerful bricks to charge multiple USB-C devices, like a drone, a camera, a computer and a phone, while editing videos and pictures on the go :-)
Thanks for the clarification - I was aware of the differences in transfer rates etc but not the charging rates - makes a shitload of sense now - thanks also to the people in the comments that further clarify the particulars
I keep two PD rated power banks with me on wilderness shoots. What a game changer. Have had no problem running my R5 in remote area of Death Valley for several days. On running a camera off the battery bank: The camera has some sort of power management circuitry. It can either charge a battery or run the camera, but not both at the same time. To Run off a PD bank you still need a battery in the camera at least in a Canon R5. To charge your camera it usually needs to be off. I say usually because after a big trip with lots too off load I find the Canon R5 will go into a sleep mode after a transfer and in this mode will charge also, even while on. It works for my work flow, transfer overnight, wake up to a fully charged camera ready to go.
Very necessary and educational video! Thank you! I, though, keep things simple, All my current cameras are using the same family of batteries, 6D2, R, R6, So I just keep a dozen batteries charged if I am going out on field. Swapping batteries is still the fastest! I do have at home/studio a bunch of Canon charger for the batteries. Not a big fan of charing using USB ports on the camera.
2:03 No you should not. The camera battery (like typical ILC batteries) is 7.4 volts but the power bank is 3.7 volts so you get only half and even them there are losses which would be 30-40%. You'll likely get two charges.
This is correct. Amp*hours doesn’t mean much without considering voltage. It’s why Watt*hours is often a better way to think about capacity. In this example, the power bank comes out to 37 Wh while the Olympus battery is 12.8Wh. Energy loss is relatively low when transferring between batteries. You should expect a bit more than 2.5 charges. Definitely not 5.
...and I just been Live Streaming 3x 90min per day in the last 3 weeks for a major car brand, using 3 fujifilm cameras on PD chargers, works amazingly fine and smooth.
Thanks. Informative. The issue I have is I heard about non certified pd splitters and u use a certified source and certified cable connect something that through handshake protocol asks for 20v, then you have a 5v device plugged in too that's also getting the 20, you fry the 5v whatever device. I understand certified devices would prevent that, except the uncertified pd splitters may not regulate the 2+ outputs A source w/ multiple outlets each individually regulated, that would be safe
Great stuff, man I wish you would have cleared demystifying using a Power Bank to charge your Camera and a Monitor like the Atomos Ninja V simultaneously. There’s so much vague information out here on this solution and how to do it safely.
As some people already pointed out, the mAh value written on powerbanks are wrong (may I say fake ? powerbank that show real mAh value are extremly rare) because of 3 main steps that will drasticaly lower real value that your smartphone or camera battery will receive, so here is the complete explanation (let say we have a "10000mAh" powerbank ) : Loss step 1 : this first step is not really a "loss" but a simple power conversion because internal Li-Io or Li-Po battery voltage is 3.7V and not 5V => 3.7 * 10000 / 5 = 7400 mAh so best case in best world you loose ~26% over 10000mAh value but there are two more steps that will reduce this value again. Loss step 2 : the 3.7 to 5 voltage conversion is done thru an electronic component called DC-DC Boost converter, but this converter (there are tons of models on the electronic market) is not 100% efficient so you loose some power during conversion usually between 5 to 10% so let say you have a good one with only 5% loss => 7400 - 5% = 7030 mAh Loss step 3 : the funny thing is that your smartphone or camera will receive 5V (if standard USB voltage no fast charge) but will have to drop down the voltage to feed the battery with 4.2V thru another electronic component called DC-DC Buck converter and here we go again with some 5% efficiency loss => 7030 - 5% = 6678,5 mAh Many powerbanks can also provide different output voltages if USB Fast Charge, 12V jack ... but all this start from internal 3.7V voltage with the 3 steps anyway. Final result : with a 1000mAh you really get 6678,5 mAh tis is a loss of ~33% so if you don't want to be dissapointed about real capacity you should always remove this pourcentage value to the value showed on Powerbank package. Note : of course if you charge your smartphone or camera and use it at same time you'll have also power loss because power from the powerbank will go to feed the smartphone or camera itself so you'll have less going to feed the battery.
-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!!!
Really appreciate that info Matt! It's fantastic info to have for our viewers!
what about the S5
Very good information and Pany users will appreciate it so much. But as a Sony user I feel so pissed that they didn't mention about any sony cameras in the video while the whole video was recorded on a sony camera! How the hell should I know how my cameras will act in similar situations? Maybe a Sony employee is also needed here while DPreviewTV doesn't give a s*** about any other brands users than the canikon.
I don't think it's necessary to go down the well trodden path of biased, brandist accusations on our part. We simply didn't mention Sony because firstly we don't want to get into every single possible permutation of camera and powerbank compatibility, and secondly because Sony cameras are very flexible and we've never really had an issue charging them. Although I believe the latest Sony cameras are PD compatible, they don't require PD chargers to charge the batteries. The only real issue we ran into so far was Canon, so we used them as our example.
@@niccollsvideo Thank you for the enlightment and information. I didn't mean that anyway. Just got pissed and felt I'm watching a video from a decade ago when we Sony Alpha users been ignored in most of the photography contents. Honestly I get surprised whenever I watch an old review of a Sony A-mount camera on RUclips and feel the dominance of Canon and Nikon was making most of reviewers going harsh on Sony cameras novelty in models like A77 and A99 with their best of all times rear screen mechanism and many other slt models and features.
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)
THIS ^^^^
Is crucial that this is clarified in the video, because even the manufactures of powerbanks use examples of how many times a certain battery can charge a certain phone. For example, Anker may say that its 10.000mAh powerbank can recharge an iPhone 12 just 2.5 times (just an example); if you do the math, it will never add up, and that's just because of the power lost in the conversion due to the output through the USB port.
Exactly! It's very sloppy to mislead viewers by implying Ah would equate capacity. It's like the whole "this tiny camera is 25-300 mm f/3.5" nonsens all over again. DPReview has learned equivalence of optics, and now needs to learn the equivalence of power.
@@LuizAlejo No, it's not the losses from conversion, but the actual capacity difference. The Ah of different V aren't comparable. Doubling the V will halve the Ah, and vice versa. Losses come then on top of that.
Yup, it's well below 3 charges for that specific battery. There's loss from converting the 3.7V from the batteries in the powerbank to 5V (assuming it's using 5V), then the camera's internal conversion from 5V to 7.4V.
This is true (I was going to post the point myself).
Let’s face it, the power bank manufacturers do this to confuse buyers into thinking they’ve got more capacity than reality. Dpreview fell for it… but they wouldn’t be the first!
We appreciate the corrections on the capacity of batteries, and losses of energy whilst converting. Thanks to everyone for helping to clarify this situation!
u cute
Did you know you made a mistake on the internet?
Don’t worry, six million people that have nothing else to do will make it their sole mission in life to nip at your heels because this mission is more important than the meaning of life.
Loved the vid.
@@agenericaccount3935 Correct information is important. It is easy and appreciated to provide an update/correction/whatever in a civil tone that benefits not only the content creator but the viewers.
@@anthonyc1883 Calm down. It’s a video about chargers. It’s not especially critical.
@@agenericaccount3935 Calm down? What a laugh. You're the one who wrote line after line after line about people who make corrections on the internet. I made no correction, I simply pointed out that there's a polite and civil way to do it. But I'm the one who needs to calm down? OK, guy.
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! 😂
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.
I paused the video to type the same thing. Thanks for lifting the burden of being the "AcTualLy..." guy from me.
Nice to see I was not the only to notice. I was expecting him to say "but..."
It's not picky if the error results in 2x fewer full charges being claimed in the video.
yup, thats why you gotta use WHr and not mAH
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.
Isn't Apple's power brick the only one that supports it so far? Looking at the size of that thing, despite it using GaN, I worry about the availability and size of PD 3.1 chargers in the future, lol.
Indeed. Some new smartphones (Xiaomi Mi 11 Ultra I think) are shipped with 120W chargers!
Great video. Yes, a video explaining the I/O data protocols and transfer speeds would be of great interest.
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!
I'll never miss the dislike button for this channel! Lots of love ❤️🙌🏼
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.
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 !)
This is why I am not a physicist.
To be fair, everyone should be picky about units if we want to understand anything at all. Although sometimes you can guess what people mean when they say something stupid like "fast speed" (usually meaning high speed, not high acceleration, which it actually means) or "cheap price" (meaning a low price, which was acquired for free by looking at the sticker on the product).
And it's not only related to science. E.g., check out the short discussion Alice has with The White Knight about "A-sitting On A Gate" (a song, which name is called "Haddocks' Eyes").
Thank you so much for using the metric system. It would have got way too complex if you used USA units of BTUs.
Hopefully the USA will change over soon to simplify other unit conversions.
Agree.. And referring to the Zed5
Thank you for this. Clear explanation that I have searched for and not found anywhere else.
Great content!
...now you need to repeat it with every single camera brand on the market!
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.
Great video, I didn’t know about the pd specification. Thanks a lot!
Would definitely love to see more videos about data transfer rates, efficacy and adaptability of cables, and all that kind of techno-wizzardry of work arounds and make-do. The current scope of tech is amazing and confusing in equal measure
Very informative 🤔 I wasn’t aware of this complicated mess when it comes to charging. I’m more “in the know” when it comes to data exchange speeds with all these different protocols though.
Would love to hear your thoughts on USB-C data, thunderbolt etc. Thanks
Idk why I'm watching this, I'm an electrical engineer...
😂😂😂😂
Long time fan of DPReview. Great video! thank you
Good information......small correction.....power banks typically use one LiPo cell at the rated capacity or more in parallel combining to the rated capacity. They are 3.7 volts nominally and are max at 4.2 volts. This voltage is increased by a circuit to the 5.1 volts needed. This can not happen without reducing the rated capacity ( ie 10,000 mAh power bank can not deliver 10,000 mAh at 5.1 Volts) There are powerbanks that deliver higher voltage using a similar arrangement.
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
No, it wasn't spot on, because he doesn't know even the very basics of electrical power. He uses Ah (incorrectly calling it A/h) when he should be using Wh. See other comments above for correct information.
Best video I have ever watched that explains this concept the way I will understand it easily.
So helpful. I’m using DJI drones and SONY cameras. Now to get it all charging fast as possible. Thanks. Kent / Montana
Clear explanation of a complicated subject!
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!
Excellent video. Never heard of PD! Please do more like these. Thank you.
Thank you so much for making a video about this and trying to make it as easy as possible. My brain still hurts anyway... Long live analog photography!
Very useful, after buying several new chargers and cables thinking it will save me time and convenience by giving me super fast charging, now I realized they are not going to do that. PD cables and charger is what I need!!!
This may be an unpopular opinion, but I prefer having the wall charger over USB solutions. USB solutions are always a secondary method of charging convenience for me. While all of the increased wattage is great for the newer USB and Thunderbolt specs, that increased wattage creates excess heat, which, in my experience, is not the best for prolonged use of electronic equipment or batteries. Wall chargers tend to be much better at managing this than USB power options are and, to me, at least, seem safer and more reliable than USB solutions. Furthermore, USB C connectors have this nasty habit of falling out of their ports after extended use! We need a better semi-locking connector especially for power or audio connectivity in our devices. Excellent video, as usual!
I agree. I much prefer wall chargers. I can buy two batteries, charge one at the wall, while using the other. With USB charging, when my battery is dead, I have to plug in the camera, and it's not available to use - unless I buy both a second battery AND a wall charger. I don't see the advantage of USB charging over wall charger.
Another point against USB charging, and this may only refer to some cameras, is that it takes a long time. My old Nikon D5100 batteries would charge in 90 minutes in the wall charger. My current camera, a Fujifilm x-s10 takes around 4 hours or more to charge the battery in camera!
heat comes from inneficiences on conversion or badly graded cables for the current they supply.
Dc to Dc charging is far more efficient than ac to dc.
LOL…slow news week guys?
Still, for a dry topic, all the dirty talk made it quite good!
Appreciate your stuff!
You cannot expect 10000mAh battery to charge Olympus battery 5.8 times. You have losses (like thermal) that will significantly lower the number of charges.
Yes that's obvious, but he's simplifying things. The video says "USB Power for Dummies".
The math on the screen showed 5.8 but he said just over 5 times, which may be possible.
10 Ah at 3.7 V is equivalent to 5 Ah at 7.4 V. Actually you should be using Wh instead of Ah. To get the Wh you multiply the Ah by the V. 10 Ah at 3.7 V is 37 Wh.
It's actually worse than that. Amp hours, unless the voltages are the same, cannot be divided like that. If you look at the footage, the bank is labeled 10,000mAh and 37Wh, which is the rating of the 3.7V (nominal) batteries inside, 10000mAh x 3.7V = 37Wh. The camera's battery is rated 7.4V at 1720 mAh, and 7.4V x 1720mAh = 12,728mWh = 12.728 Wh. The bank can charge the battery 2.9 times at most, before losses are considered.
I'm an Emergency Room Psychiatric Clinician, and for years, I've wondered how you guys still roam free. To get back on topic though, things have been such a maddening mess since the Pandemic, and seeing as how these PD chargers are capable of delivering such a stable flow of reliably high current, I was wondering if you or Jordan have any personal knowledge on the off label use of these devices as Electro-Convulsive Shock Therapy Delivery Systems. There is such a profound shortage of Mental Health resources at this point in time, this might be just the ticket.
Thank you so much for your brilliant work. You guys keep me relatively sane. =)
Great video thanks for the upgrade in my education!! 😎
The Olympus E-M1 Mark III can be charged by standard as well as PD power banks and it can be run via PD powerbanks. It supports PD powerbanks up to 100W
Seems good footage from the Sony A7 IV. Thanks for the information, didn't know about differences in usb c cable ratings.
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.
Excellent!. Not many people knows the information!!
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???
It is not labeled next to the port, but Sony A1, AS7m3 and A7m4 all support PD but do not require it to charge the battery.
You learned a new word to substitute other words with and now you don't need to think as much to use the proper words. Just got to bleep or silence them out. Good for you.
Really strange that Nikon and Canon can't implement a "slow charge" mode at 5V, just like Sony and I think Fuji, where a non PD charger can charge the camera - slower, but at least it charges. Which can be a huge difference if you are far out in the world on some job and have forgotten your PD charger or it broke.
Just sure the info in Nikons manuals is wrong. I have a Nikon Z5 and it charges just fine on non-pd usb-bricks.
@@Stonebrass Hm, interesting. I'll check whethey they are wrong here.
Very well explained, I learned some very useful things about USB-C and PD.
Thanks for sharing!!
I wasn't sure whether to watch this one but did learn a couple of useful things. Thanks!
this came at the right time I was wondering why my a7siii wasn't charging now I know why. Thank you
After frying one of my favorite Chorus pedals with a 12v power supply (it runs at 9v).... believe me, this is a great reminder that all our glorious tech is worth fuzz all if one doesnt look after it properly, and powering things properly is definitely the most important thing.
Fantastic, Thanks! Maybe touch on these universal camera battery chargers in a future video. I like to charge my removable batteries outside the camera.
Came here looking for answers on what type of USB charging ports would be best to integrate into a "charging" end table for my living room. Everything here was dumbed down to my level of understanding perfectly.
Super interesting video boys. Well done. 👍👍
Thunderbolt is a blessing for modern cameras. Power delivery is one thing, but also having the data transfer rate of Thunderbolt for some of these giant raw files and 4k/8k video to work on is the bigger benefit in my workflow. It is nice that my Macbook doubles as a power bank for my camera in an emergency lol.
Excellent presentation. Greatly appreciate you took the time to put this together.
Great stuff Chris, just purchased the Canon R6 and was having that exact issue. I found that my Samsung S20 charger works to charge the R6, but none of the other hundreds of cables and USB plugs seem to work and know I know why👍😎👍
Thanks. I just got a Samsung Galaxy s22 ultra, capable of 65w charging but I didn't have a charger capable of delivering that amount so I bought one, but reading the label I saw many different outputs and I was confused. And because I wanted to know if I could charge my laptop (45 Watts) and other devices such as my headphones (which I doubt could resist that amount of power) I wasn't sure of what to do. And now thanks to you I got all the answers I needed. Thanks a lot!
OMG, at the third minute, my brain just blew up. It's not you Chris, I clicked on the video, it's me.
Perfect information!
The lack of cable labelling is a mess.
Great video, but I think you also need to cover PPS... ideally to fully cover the gamut in pursuit of "one charger to rule them all", it needs to be USB C PD 3.0 PPS compliant, and 65w or greater (such as the Anker powerport lite or Anker Nano II).
Wow, that was super helpful. Love your channel, content and the professionalism with which you deliver your content.
Best i didn't know i needed to know video, thank's for sharing guys and yes i would be interested now, to learn more about the different capabilities and transfer protocols of the different cables out there. I'd watch such a video for sure.
When I saw the title of this video I thought it won't be very interesting, how wrong I was. My wife and I recently went to Spain on holiday, we took 3 cameras, so 3 old fashioned wall plug type chargers, we took 3 mobile phones, so 2 more cables and chargers, and a laptop with its own charger, all those chargers took up space and more importantly were heavy. Perhaps I can consolidate them down and use a power bank, unfortunately only one of the cameras supports USB charging, but as I am thinking of getting a new laptop, your advice on a Thunderbolt port will be useful. So, thanks for the video, if you don't watch then you don't learn.
im waiting for the 2.4 jiggawatts version to power my flux capacitor :) good video and good explanation of all the crazziness.
1:30 US Citizen: „What! How can conversion be so easy? Shouldn‘t this be like 8.4375743 times x?“ Rest of the world: „Metric system, Baby!“
Once again a great resource info package on stuff everyone deals with one way or the other, highly valuable and important details, beautifully done - thanks so much!! One aspect though should have deserved some more attention, and that is the question about whether a powerful charger can possibly hurt a small device, like using a laptop charger that can send 65W on a camera or cell phone that needs only 5W to 20W for example. You briefly mentioned the handshake technology (always reminds me a bit of two fax machines exchanging their noisy spec info while negotiating their fastest common denominator), but I believe a lot of folks would have found it comforting to hear a bit more about what might and what will not hurt our sensitive equipment.
Running an R5 from USB needs 9v at 3a, I'm told (27w) ... New PD charger arriving today, looking forward to playing with it!
Oooohhh volts amps & wattage! Energizing! more coffee needed too! ☕️
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
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.
Thank you for this. Its a mess trying to figure it out. Would be great to do a video about D-tap V-powered etc ..
DPReview did a better explanation than LinusTechTips. Damn.
DPReview's explanation was wrong. Damn.
Very well done and that complement comes from an Electrical Engineer who spent time designing charger IC for smart phones. It might be nice to add a brief addition for PD vs Quickcharge vs IQ3 chargers and their cross compatibility. Take care.
Fantastic video for a "Touch of Gray" model... thanks!
I'm ok with that. I want you to at least get something out of our videos.
@@niccollsvideo LOL.
@@niccollsvideo The video content was awesome! Very, very good information!!!
@@scottslotterbeck3796 Now I can't stop laughing either, baaaahhhhh
I do want Chris' hair. Well, not LITERALLY his hair, I mean that's creepy, but...
I think he should do a commercial for 'Touch of Gray'.
Really good and informative video. Thanks!
It's worth mentioning that multi-voltage/amp ratings on the charger can also indicate other standards like Qualcomm's QuickCharge or Mediatek's Pump Express. Those will have USB A ports, though, but will also have 9V and 12V outputs in a lot of cases.
That being said, every time I've charged a USB PD device using a type A to type C cable into a brick that only supports QC (QC2.0, in this case) it has triggered the higher voltage/amperage charge modes, and the same when using a QC device with an adapter into a USB-C PD specced charger. Not sure if it's intentional backwards compatibility or what.
Just what I needed to know, and more. Thank you!
This was an excellent and needed video. After watching every cell phone on earth go to usb-c I was shocked that cameras were still stuck in usb-micro (a6400etc) When the zv-10 was released most reviews did not even mention the usb-c port. Transfer rates and charging are so improved it would be excellent if you could educate us more on the new capabilities of the newer cameras with usb-c. Thanks.
This is a very useful video for the layperson. Just wanted to clarify that most power banks advertise mah ratings based on 3.7V nominal, which is NOT typical of devices (usually they are at 5V). So the TRUE mah available is actually considerably less. A good rule of thumb is about 66% of labeled rating. So that 10,000mah power bank will actually peter out after having dished out a total of a little over 6000mah to any devices plugged into it. ;)
@chris, this is a fantastic video. So much of this basic stuff is usually overlooked but is actually critical to successful production especially in the field. You did a great job explaining things without getting too technical. Kudos on that.
A correction: you said a 10,000 mAh battery pack can charge a 1720 mAh battery, 5.8x, but your math is based on being able to use all 10,000 mAh. The fact is that you can never get ALL of the 10,000 mAh out of the battery pack- you can never deplete the cells to zero. All cells have a "base" capacity where you simply can't draw any more.
Moreover, lithium packs have controller boards that will stop output to protect the cells. The same goes with the battery pack for the camera. It's 1720 mAh, but you'll never drain it to zero.
It's almost impossible to know the exact actual "usable" capacity of the battery pack because it's dependent on the type of cells, the number of cells, quality fo the cells, etc, and much easier for the manufacturer to just label with total capacity.
Secondly, you noted that all kinds of PD rated gear can be charged by universal PD rated adapters.
You say this is more convenient than separate AC battery chargers.
I find having a battery on a charger, separate from using my camera in a gimbal, to be far more convenient than trying to power the camera with a wire, or charge it while using it. Your mileage may vary.
This is especially relevant for camcorder batteries like the ubiquitous NP-F (Sony Infolithium-L) battery that is used for cameras, lights, monitors, and a lot more these days. A single 7800 mAh NP-F can run gear for hours at a time, while another set of batteries are getting juiced back up in "video village." I find a 5 second battery swap to be the most convenient solution for mobile filming than having my camera tethered to an external power source.
Also, as a Panasonic employee noted on the RUclips video- some devices can't charge and run the camera at the same time, or can only trickle charge if the camera is running, and either of those are dependent on the wattage of the power adapter / battery bank, and the capacity / capability of the camera to draw and utilize enough power to do one, or the other, or both. Making t a lot of cross referencing minute, obscure, and sometimes simply unavailable specifications. Again, making the case to charge the batteries externally.
This is what works for me.
Again, Kudos on a fantastic video about an important, and near universally overlooked topic.
Great vid. More of this type of content would be great. eg data rates, tips for charging multiple devices/batteries etc
It all started as video for Dummies, but after all I got some new info :). Thx.
Great job on the video, I've been working on something similar though not nearly as detailed. The Nikon Z5 seems a lot less picky than the Canon M6 Mark II that I have. Those two cameras have gotten me exploring USB-C cables and chargers. Definitely has been a journey, lol. I agree that if you can find the right combination of components it's more convenient and travel friendly than old direct charging adapters.
Great video - it really helped me cut through the confusion of USB-C!
Very helpful and clear presentation. More like this would be very welcome. Great job!!!
it's really time we'd find a solution to label our cables. As a full-time traveler constantly updating my gear, it's a real PITB... and finally getting powerful bricks to charge multiple USB-C devices, like a drone, a camera, a computer and a phone, while editing videos and pictures on the go :-)
This was extremely informative! I would love to see more videos on USB (and/or Thunderbolt).
Thanks for the clarification - I was aware of the differences in transfer rates etc but not the charging rates - makes a shitload of sense now - thanks also to the people in the comments that further clarify the particulars
Ok, very useful and good video, BUT all I want is the Christmas video with Best and Worst, AND shots. 😅
I keep two PD rated power banks with me on wilderness shoots. What a game changer. Have had no problem running my R5 in remote area of Death Valley for several days.
On running a camera off the battery bank: The camera has some sort of power management circuitry. It can either charge a battery or run the camera, but not both at the same time. To Run off a PD bank you still need a battery in the camera at least in a Canon R5. To charge your camera it usually needs to be off. I say usually because after a big trip with lots too off load I find the Canon R5 will go into a sleep mode after a transfer and in this mode will charge also, even while on. It works for my work flow, transfer overnight, wake up to a fully charged camera ready to go.
Very necessary and educational video! Thank you! I, though, keep things simple, All my current cameras are using the same family of batteries, 6D2, R, R6, So I just keep a dozen batteries charged if I am going out on field. Swapping batteries is still the fastest! I do have at home/studio a bunch of Canon charger for the batteries. Not a big fan of charing using USB ports on the camera.
Super useful info, Thanks! 'Learned some new stuff today that I had no idea about.
You made this simple. Thank You
2:03 No you should not. The camera battery (like typical ILC batteries) is 7.4 volts but the power bank is 3.7 volts so you get only half and even them there are losses which would be 30-40%. You'll likely get two charges.
This is correct. Amp*hours doesn’t mean much without considering voltage. It’s why Watt*hours is often a better way to think about capacity. In this example, the power bank comes out to 37 Wh while the Olympus battery is 12.8Wh. Energy loss is relatively low when transferring between batteries. You should expect a bit more than 2.5 charges. Definitely not 5.
thank you. please do one about usb c cables, TB 3/4 etc.
...and I just been Live Streaming 3x 90min per day in the last 3 weeks for a major car brand, using 3 fujifilm cameras on PD chargers, works amazingly fine and smooth.
Thank you so much! I thought i know so much until lately with so many new things
Thanks. Informative. The issue I have is I heard about non certified pd splitters and u use a certified source and certified cable connect something that through handshake protocol asks for 20v, then you have a 5v device plugged in too that's also getting the 20, you fry the 5v whatever device. I understand certified devices would prevent that, except the uncertified pd splitters may not regulate the 2+ outputs A source w/ multiple outlets each individually regulated, that would be safe
Great stuff, man I wish you would have cleared demystifying using a Power Bank to charge your Camera and a Monitor like the Atomos Ninja V simultaneously.
There’s so much vague information out here on this solution and how to do it safely.
Great info............ many thanks..........
Very useful video, thanks!! My Sony is "older" now but still it's good to know. Transfer rates etc would be interesting too
Great breakdown Chris!
As some people already pointed out, the mAh value written on powerbanks are wrong (may I say fake ? powerbank that show real mAh value are extremly rare) because of 3 main steps that will drasticaly lower real value that your smartphone or camera battery will receive, so here is the complete explanation (let say we have a "10000mAh" powerbank ) :
Loss step 1 : this first step is not really a "loss" but a simple power conversion because internal Li-Io or Li-Po battery voltage is 3.7V and not 5V => 3.7 * 10000 / 5 = 7400 mAh so best case in best world you loose ~26% over 10000mAh value but there are two more steps that will reduce this value again.
Loss step 2 : the 3.7 to 5 voltage conversion is done thru an electronic component called DC-DC Boost converter, but this converter (there are tons of models on the electronic market) is not 100% efficient so you loose some power during conversion usually between 5 to 10% so let say you have a good one with only 5% loss => 7400 - 5% = 7030 mAh
Loss step 3 : the funny thing is that your smartphone or camera will receive 5V (if standard USB voltage no fast charge) but will have to drop down the voltage to feed the battery with 4.2V thru another electronic component called DC-DC Buck converter and here we go again with some 5% efficiency loss => 7030 - 5% = 6678,5 mAh
Many powerbanks can also provide different output voltages if USB Fast Charge, 12V jack ... but all this start from internal 3.7V voltage with the 3 steps anyway.
Final result : with a 1000mAh you really get 6678,5 mAh tis is a loss of ~33% so if you don't want to be dissapointed about real capacity you should always remove this pourcentage value to the value showed on Powerbank package.
Note : of course if you charge your smartphone or camera and use it at same time you'll have also power loss because power from the powerbank will go to feed the smartphone or camera itself so you'll have less going to feed the battery.