So I found my next flashlight.

I was browsing on Temu, AliExpress’ rapidly rising competition, and I came across the bargain of a lifetime. For less than three dollars, shipped, I can get this technological marvel:

​

So exciting! 98kW for 980 hours is 96.04MWh! For less than 3 bucks! Now charge time is probably a bear, but I don’t see having to charge it any time soon. Also, I could use to run my house, and nine neighbors for about a year.

I am a bit worried about shipping, though. 96.04MWh is about 3.46x10¹¹ Joules! A ton of dynamite is 4.148GJ so that battery is sporting about 83 tons of dynamite’s worth of faulty 18650 YouTube video. Still, can make progress without risk. A few cities wiped off the map to move into the new age of the $3 flashlight economy is well worth it.

 

You could do a lot of damage with 49kW concentrated into an area of 3cm^2.
And if it's the most efficient LED in the world, it's about 50% efficient. Let's assume that 98kW is the power it consumes, so the device held in that hand is dissipating 49kW.

 

he device held in that hand is dissipating 49kW.

that oughta get real hot real quick ...

 

You could do a lot of damage with 49kW concentrated into an area of 3cm^2.
And if it's the most efficient LED in the world, it's about 50% efficient. Let's assume that 98kW is the power it consumes, so the device held in that hand is dissipating 49kW.

It might get a little warm. I am pretty sure that it will start some fires if you turn it on, but progress takes some sacrifices.

 

It's got a pretty good range, too. But the curvature of the Earth might be a limiting factor.

 

Liars! It's 0.02 cm short of 90km!

 

It should charge in just under 47 years at the highest USB-C output.

 

I am pretty sure it is powered from a fusion reactor. I hope you can find enough deuterium.

 

Liars! It's 0.02 cm short of 90km!

View attachment 298030

You have to read the fine print.

 

It is sad but probably inevitable that there is even any utility in making such absurd claims. In a closer-to-perfect word, a high school education would be enough to immediately recognize the physical impossibility with a very basic intuition for the meaning of units of power relative to everyday experience.

It reminds me of a somewhat tangential but related story—it’s a true one that I appear in.

When I was working at the university in the electrical engineering department I was standing in the office with a colleague—let’s call him “Phil” (not his real name)—a faculty member with a research program in MEMS technology, among other things. Phil had an Indian PhD candidate RA—we’ll call “Raj” (also a pseudonym)—who had a masters in physics from an Indian university. It seemed like all the Indian students we got seeking EE PhDs were either mathematicians or physicists.

Raj was an otherwise well educated and intelligent person, and quite likable. But he definitely had the demeanor of a physicist. If you’ve worked around physicists you probably know what I mean. One fabled trait of that noble class of seekers of higher truth is their attachment to order of magnitude estimates, something that engineers find variously humorous and infuriating.

So on this day we were standing in the office and Raj walked in. Raj was assisting Phil with a project that involved an implantable MEMS device to inductively couple a small current to electrodes in the body. There was an important question about how much power would be dissipated at the device in order to get sufficient power to the electrodes.

In an effort to answer that, Phil had purchased. (in a typical way for him) a specialty power meter from eBay. He was quite frugal and had discovered eBay could be a big money saver. The meter operated perfectly so far as they could tell but the operation of it was far from obvious and no manual was included with the purchase.

So, Phil had tasked Raj with contacting the manufacturer to get a manual. An apparently simple thing but maybe not for a physicist. Raj had procrastinated and today Phil was ready to make an ultimatum that it would be done post haste. So, it confronted Raj and it went something like this:

Phil: Did you get the manual?​

Raj: No, not yet… but I did work out how to calculate the power!​

Phil: You did? Great! How much is it?​

Raj: (Hesitating) erm... about 500W.​

Phil: 500W! That would set them on fire!​

Raj: No, no... sorry… 50W​

Phil: 50W!? Do you know how much 5W is!?​

Raj: I…​

Phil: Do you have the phone number for the company?​

Raj: (Hesitating) I…​

Me: He’s going to give you estimate.​

Phil: (Laughing out loud, really) Ha, yes—it’s about 8 trillion!​

So, even degreed physicists sometimes can’t work out if a power claim is reasonable. What hope is there for the average denizen of the Internet?

 

For less than 3 bucks!
[...]
I am a bit worried about shipping, though. 96.04MWh is about 3.46x10¹¹ Joules! A ton of dynamite is 4.148GJ so that battery is sporting about 83 tons of dynamite

Surely you're not expecting a $3 device to ship with $20k worth of charge in it?

It should charge in just under 47 years at the highest USB-C output.

Not to worry though, it won't cost much as we can do this from 5V/500mA.

 

In fairness to physicists, they routinely work with power levels that appear completely unreasonable to most engineers -- usually by concentrating relatively small amounts of energy into absurdly small amounts of time. The result is pretty naturally that they end up lacking a good feel for what are and are not reasonable power levels for more mundane situations.

 

Surely you're not expecting a $3 device to ship with $20k worth of charge in it?

Why not? For a long time people said that the way to get around electric vehicle charging time when on the road is to swap out batteries the way that propane tank exchanges work -- so swap out $20k worth of batteries with $3 worth of charge.

 

24 BitCoin Miners running at about 120 TH pulls about that much power (90kW) .... OR .... about 50 Homes using about 35kWh a day to put it in more perspective.

 

Back in the 1970's time frame (give or take) there was an ad for a TV antenna -- just a plain old antenna that you would set on top of the TV. The ad had all kinds of absurd claims, but the best one was "A marketing breakthrough!".

 

Why not? For a long time people said that the way to get around electric vehicle charging time when on the road is to swap out batteries the way that propane tank exchanges work -- so swap out $20k worth of batteries with $3 worth of charge.

That's not quite analogous to what I said. It would be like buying a full propane tank for the price of an empty one. When the tank costs $30 and the propane inside costs $20k.

But it was a joke and I'm not sure if your reply was joke. I probably just killed it if it was. Sorry.

 

Possibly 98000W us just the model number.

 

Back in the 1970's time frame (give or take) there was an ad for a TV antenna -- just a plain old antenna that you would set on top of the TV. The ad had all kinds of absurd claims, but the best one was "A marketing breakthrough!".

I remember that.

 

Possibly 98000W us just the model number.

And “980 hours” is the part number.

 

Snake lost that eye using that flashlight on a mission.