DPReview TV: USB power explained - what you need to know

Also, as a Panasonic employee noted on the YouTube 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 it a lot of cross referencing minute, obscure, and sometimes simply unavailable specifications.
Again, making the case to charge the batteries externally.

No, he means what he said: micro USB plus an extra part to the connector that you rarely see. I have such a cable, and the Panasonic G9 accepts it.

I would add to your 5 points on Olympus cameras

6) USB-C on E-M1iii can support PD or data but not both at the same time.

Tethering an E-M1iii to a PC via USB-C enables the PC to control the camera but doesn't power it. For a prolonged tethered shoot you have to provide power by another route. I use the 9V DC input on the HLD-9 grip which adds bulk and another cable to manage. I don't know if the issue lies within the USB-PD specifications or in Olympus's implementation of them.

10 amp hours (10,000 milliamp-hours) at 3.7 volts nominal is 37 watt hours. So 100W is almost 3C discharge and charge.

3C discharge is doable (albeit potentially only with cells optimized for power and not capacity), 3C charge is generally a bad idea for most chemistries.

your (MBP) M1 Max has a 100Wh battery, so what would a small 10,000mAh/3.7V = 37Wh powerbank be of use to you? With charging losses you'd be lucky to add 25% to your MBP battery...
You'd need a 40,000mAh one to fully charge an empty MBP battery.

If you still want a small one, this one's only 20,000mAh and charge at 100W:
https://www.aliexpress.com/item/1005002740514937.html

If you're concerned about weight, get spare batteries to fit your camera. No way an external pack is as light for the capacity.

While most of the cameras talked about in dpreview still have external batteries (and most have external chargers for those batteries), I recall looking at action cameras and there a lot of the units have no external battery. You have to charge the battery via USB and usually the camera is unavailable while charging.

A hidden problem with non-removable batteries is that batteries often degrade over time. I've seen recommendations that you should consider replacing batteries about 3-4 years after they were made. If the camera (or cellphone or laptop) does not have a replaceable battery, you typically have to trash the item and replace it.

Even with replaceable batteries, you can get the problem that after a camera maker has gone out of business or switched to a new battery type with latest models that the original batteries are no longer being made. You can switch to third party batteries but the problem is most third party batteries are cheaply made and not reliable.

The M1 sips power, that's its main selling point. Can't you just leave it turned off til import/edit time, use it, then turn it off again? If all the glowing M1 reviews are correct, then you should be able to do this for five or six days at least, on one charge.

Edit: Can see this being very good use case for M1. There's no way my current laptop could do that. Or that I'd want to carry it on the hike because it's a big ole' gamer special ;-)

@PremiumBitter Your unique user case :

"25% is exactly how much I'm looking to add"

"Charge (my M1 Max) at 100W"

"Less than 10,000 mAh is perfect"

"20,000mAh is way to heavy" (it's 490g/17oz)

And you're surprised nobody makes these for you (only) :-D

Bolton: that is true, but also, it's often literally cold booting. Laptops will report (falsely) that their battery is dead when they are at -10F and colder (as they are on glaciated peaks). But if they are plugged in, they will boot up. Once they are booted up, they run reasonably well without needing to be plugged in anymore.

"25% is exactly how much I'm looking to add!

Again, weight is my #1 concern. I am a mountaineering photographer/videographer. My workload is not typical. I love how when you ask a question on internet forums, instead of getting an answer, you get something "why would you want to do that?!" So helpful!"

You should have stated in your original post that "25% is exactly how much I'm looking to add" and nobody would have bothered (to answer) you.

"the 16" Macbook Pro as a 8,000mAh battery and charges at 100W. It doesn't seem unreasonable that people would want a 100W-capable battery bank at around 10,000 mAh, given that these laptops are selling so well that they are backordered well into February. This would be enough to fully charge (almost, long story about 140W fast charging...) the computer one time."

You make the same beginner's mistake as Chris does in his video (at 2:00): comparing (m)Ah between battery and power bank to calculate how many charges you have - as explained (see my post from 3 hrs ago as well as the numerous responses to Chris on YT), you need to compared the (m)Wh capacity (as that's the energy unit).

In doing so you'll find a direct relation between (m)Wh and the weight of power bank - even you cannot defy the physics involved.

Please do your homework before you get back (again)

"You should answer questions rather than asking more questions that are irrelevant to answering the original question!"

You should try to grasp the basics before asking silly questions (to be answered)

PS: you could ask someone to make you a 8,000 mAh 100W PD powerbank, but at 18V (in stead of 3.7V), which would be able to charge your laptop fully. However, it'd be roughly the same weight as a 40,000mAh/3.7V powerbank :-D

"Laptops will report (falsely) that their battery is dead when they are at -10F and colder (as they are on glaciated peaks). But if they are plugged in, they will boot up."
And that's why what you want is literally impossible.

If the laptop's own 100 watt-hour battery can't provide the juice at 1C discharge, what makes you think a 37 watt hour battery with the same chemistry at the same temperature is somehow going to achieve 3C sustained discharge?

For reference, my car can only do about 2.3C discharge (150 kW from a 66 kWh battery) for very short bursts, and needs to heat up the battery to do that. It can only exceed 1C charge rates for a few seconds at most, and barely, and only if the battery is above 40F.

or just get a spare set of the original - all (six) are tiny and light, easy to distribute over your mountaineering clothing: https://guide-images.cdn.ifixit.com/igi/fmJJVm2mHBL6SAGJ.full

:) So true!

PD is so upto date they updated a few months back . -) USB PD is now up to 2.1. But at least at 240 watts almost everything short of a desktop should be okay.

PS: In reality you'd only be able to charge that battery twice with that powerbank, due to charging losses.

I also thought about that when I saw the video. The hotter things get the higher the loss will be since parts of the energy is not used for charging but for producing heat.

Yup and the internal voltage of the powerbank seems to be 3.7V ( 3.7V*10.000mAh = 37Wh) whereas the camera battery has 7.4V Internal.

These voltages inside the device have nothing to do with input or output, but when they are not printed on the thing people might think the given max current in 1 hour (in mAh often) is the capacity.

Just remember:
electrical Power is Volts*Amps, or VA = Watts.
And Capacity is Volts*Amps-hours, or Wh = Watt-hours

Volts alone, Amps alone or in this case mAh's alone mean nothing.