khanacademy.org/…/what-is-conservation-of-energy
Jokes aside, this is something an astonishing number of folks know less than nothing about.
Break science with this one weird trick
Submitted 2 months ago by MacNCheezus@lemmy.today to [deleted]
https://lemmy.today/pictrs/image/6ed4d7ba-b6bf-4cf6-b711-186760f30a73.jpeg
Comments
Johnmannesca@lemmy.world 2 months ago
StellarExtract@lemm.ee 2 months ago
Are you claiming to refute the hard evidence OP has presented?
LifeInMultipleChoice@lemmy.world 2 months ago
He’s saying if you plug the charger in it can transmute the energy into work, meaning when you exit the room you may come back to finding it sitting on the counter unplugged. As your partner wouldnt have wanted it to put a hole in the roof so they unplugged it and put it on the counter.
ArbiterXero@lemmy.world 2 months ago
Lisa!
In this house we obey the laws of THERMODYNAMICS!!
kibiz0r@midwest.social 2 months ago
AFAIK, those things estimate charge based on voltage. If a battery heats up, it’ll have higher voltage. Not necessarily for a good reason…
johnteachestech@sopuli.xyz 2 months ago
No.
He broke science.
LifeInMultipleChoice@lemmy.world 2 months ago
So did that dog chewing through one of these in the other post recently, subsequently broke the mattress and house apparently, haha
Psythik@lemmy.world 2 months ago
Is that why they’re so inaccurate that they always die around 20-30% and never charge to 100%? I figure that phone battery meters are accurate cause they can track usage habits, but how would you do something like that with a power bank?
MystikIncarnate@lemmy.ca 2 months ago
Yep. State of charge is almost entirely voltage based.
As a battery loses charge, the voltage sags.
What’s happening in the OP is that the batteries are getting a voltage bump, likely from the conversion to/from 5v on the output and the conversion back to battery charging voltage on the input (or the thermal/internal resistance is changing)… One of those things.
Either way, the conversions are not 100% efficient, so basically all this does is turn your battery bank into a heater, slowly sapping the power away from it as heat until dead.
With phones, it can also be battery degradation, that the voltage drops off at a higher “state of charge” level than when the battery is new.
Voltage sags can also be induced by load. If you go from a high drain state on your phone to a low drain state (say, going from playing a 3D mobile app to idling at the lock screen) the state of charge % can actually increase.
Cold temperatures can also increase the internal resistance and cause batteries that are not fully discharged to stop operating as well, only to work again after being warmed up.
Current battery tech is wild, and the state of charge indicator of voltage can be extremely inaccurate.
kibiz0r@midwest.social 2 months ago
Pretty much, yeah. scienceabc.com/…/what-are-the-different-methods-t…
LANIK2000@lemmy.world 2 months ago
My powerbank just detects that it is connected to itself and does jackshit.
Hupf@feddit.org 2 months ago
Just buy another one and plug them into a ring.
abcd@feddit.org 2 months ago
Just like at work: Forward office calls to your mobile. Forward mobile calls to your office phone.
Get your work done until everybody finds out and starts wasting your time again 😂
captain_aggravated@sh.itjust.works 2 months ago
I wonder by what method it does that? put out a pulse code on the power out and look for it? Some USB cables don’t actually carry the data lines through, so.
dabaldeagul@feddit.nl 2 months ago
I imagine plugging a powerbank into itself just causes a short circuit. Detecting that isn’t the most uncommon thing fafaik.
ShortFuse@lemmy.world 2 months ago
Something something ground loop detection, maybe.
Johanno@feddit.org 2 months ago
You either have a ping before connecting and if you get a response don’t do it. Or you send some high frequency wave additionally to the power. You can detect that signal and then stop accepting the power.
Basically like ethernet over powerlines work.
Blackmist@feddit.uk 2 months ago
Probably just sends a number as data, and if it gets it back then doesn’t charge.
You’re right that some cables don’t carry data, but most do and as long as the cable that comes with it does then it’s going to be fine for 99% of cases.
There’ll often be a way to break it like going through a USB hub, but most people aren’t actively trying to damage things. I can see people wrapping the cable around it and plugging both ends in to stop them flapping about though.
grandkaiser@lemmy.world 2 months ago
Big oil strikes again!!
grandkaiser@lemmy.world 2 months ago
Firefighters hate this one easy trick!
Reviever@lemmy.world 2 months ago
DON’T DO THIS. i did that by mistake once and it grilled my powerbank. was completely broken after. this is beyond studid.
todd_bonzalez@lemm.ee 2 months ago
What’s stupid is buying cheap AliExpress power banks that don’t mitigate this situation safely, and instead simply explode, burning your house down…
Persen@lemmy.world 2 months ago
They are cheap and if you don’t need an expensive product, they are mostly fine, but I got a free powerbang with some crappy teen magazine (when in still ocasionaly read those ad filled pieces of shit) and it died on the second charge.
cordlesslamp@lemmy.today 2 months ago
Assuming it was either 15 years ago or your powerbank is a budget one.
My powerbank would just flip me off and tell me to go fuck myself if I did plug it into itself.
Valmond@lemmy.world 2 months ago
Just put it in the microwave to super charge it smh.
nucleative@lemmy.world 2 months ago
Nail it to the side of your house, in the sunlight, for a totally free charge from the sun
match@pawb.social 2 months ago
the hazards of perpetual energy
ekZepp@lemmy.world 2 months ago
[The Free-Energy Trick Big Companies Don’t Want You To Know]
Wilzax@lemmy.world 2 months ago
You shouldn’t charge a battery pack at the same time you’re discharging it unless it’s specifically designed to allow that. Most consumer power banks are not designed to do that.
It’s doubly stupid to charge it from itself.
Backfire@lemmy.world 2 months ago
I once did that with a Samsung powerbank I have. Daisy chained the powerbank to charge itself and a phone in sequence.
The only thing that failed afterwards was one of the cables, but suffering a loss was definitely the reason I didn’t attempt to do that again.
boatsnhos615@lemmings.world 2 months ago
Seat’s taken
VonReposti@feddit.dk 2 months ago
I once charged my phone by holding it over an induction cooktop. Only for a couple of seconds though as I was afraid to fry my phone, but it did it over 40cm
MystikIncarnate@lemmy.ca 2 months ago
That’s actually kind of valid. Though, the induced voltage might be a lot more than phones can typically handle via wireless charging.
Not recommended, however, induction cooktops and wireless charging are the same underlying technology.
I wouldn’t gamble that the phone has sufficient over voltage protections on the wireless charging to survive. YMMV.
VonReposti@feddit.dk 2 months ago
Yeah, I had the exact same thoughts about the risk to the phone, but curiosity got the best of me. The phone worked fine for several years afterwards so no harm done.
accideath@lemmy.world 2 months ago
I always wondered what would happen…
VonReposti@feddit.dk 2 months ago
You’re welcome, now you don’t need to risk your own phone in order to know :p
Kolanaki@yiffit.net 2 months ago
I used to take those 9-volt battery connectors, wire them up together and then recharge a dead 9-volt with a brand new one until the tester strip thing showed they were both even. Surprised they never popped because they would get really hot lol
pewpew@feddit.it 2 months ago
My dad used to recharge alkaline batteries with a special charger, but that was quite useless
todd_bonzalez@lemm.ee 2 months ago
Those chargers are really dangerous. It is technically possible to recharge a disposable alkaline battery a few times, but you’re never going to get more than a half charge, and it will fuck up the internal chemistry turning each battery into a tiny potential pipe bomb.
bcgm3@lemmy.world 2 months ago
MintyAnt@lemmy.world 2 months ago
About to destroy OPs entire career with one short
DannyBoy@sh.itjust.works 2 months ago
I’ve heard the cheap ones don’t like doing this too much.
essell@lemmy.world 2 months ago
We still talking about power banks?
nexussapphire@lemm.ee 2 months ago
100w charging, getting pretty toasty!
Sibbo@sopuli.xyz 2 months ago
Ah, the flintstone of the modern age
Steamymoomilk@sh.itjust.works 2 months ago
Fire hazard speed run
JohnDClay@sh.itjust.works 2 months ago
I don’t think it would it be too bad since it’d have a current limiter would it?
JCreazy@midwest.social 2 months ago
It will only charge as fast as the output of the power bank.
Swedneck@discuss.tchncs.de 2 months ago
this assumes it’s not a dogshit quality power bank
umbrella@lemmy.ml 2 months ago
i have a similar one and its shoddy enough that i wouldnt bet on it.
captain_aggravated@sh.itjust.works 2 months ago
Just don’t let a dog do a bad chew.