• JohnDClay@sh.itjust.works
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          4 months ago

          Yeah, so I think it’d be fine, since I’d think the charge limit would be about the same as the discharge limit of the power bank. It would heat up a normal amount for charging and being charged at the same time, but I don’t think it would melt down or anything. It’d just drain slowly over time.

      • Swedneck
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        4 months ago

        this assumes it’s not a dogshit quality power bank

      • LifeInMultipleChoice@lemmy.world
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        4 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.

  • kibiz0r@midwest.social
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    4 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…

    • Psythik@lemmy.world
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      4 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
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        4 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.

      • abcd@feddit.org
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        4 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
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      4 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.

      • Da Bald Eagul@feddit.nl
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        4 months ago

        I imagine plugging a powerbank into itself just causes a short circuit. Detecting that isn’t the most uncommon thing fafaik.

        • Chee_Koala@lemmy.world
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          4 months ago

          What about all those usb handshakes? It think it will just drain itself with heat and damage the battery slightly while doing so.

        • recarsion
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          4 months ago

          Next technological revolution will be breakers in powerbanks

      • Johanno@feddit.org
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        4 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
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        4 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.

  • Reviever@lemmy.world
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    4 months ago

    DON’T DO THIS. i did that by mistake once and it grilled my powerbank. was completely broken after. this is beyond stupid.

    • Todd Bonzalez@lemm.ee
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      4 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
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        3 months ago

        They are cheap and if you don’t need an expensive product, they are mostly fine, but I got a free powerbank with some crappy teen magazine (when I still ocasionaly read those ad filled pieces of shit) and it died on the second charge.

    • cordlesslamp@lemmy.today
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      4 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.

      (seriously tho, it would just cut power and turn off immediately. If your powerbank doesn’t do at least that, then discard it and get another one with more advanced protection features)

        • Crikeste@lemm.ee
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          4 months ago

          And it was probably cheap Anker instead of expensive Anker? Maybe that shit just hadn’t hit consumer products yet as well. But yeah, Anker offers a HUGE selection of products from consumer to professional.

  • VonReposti@feddit.dk
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    4 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
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      4 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
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        4 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.

  • Wilzax@lemmy.world
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    4 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
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      4 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.

  • 🇰 🌀 🇱 🇦 🇳 🇦 🇰 ℹ️@yiffit.net
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    4 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
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      4 months ago

      My dad used to recharge alkaline batteries with a special charger, but that was quite useless

      • Todd Bonzalez@lemm.ee
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        4 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.

        • Psythik@lemmy.world
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          4 months ago

          I had a babysitter that used to do that. Even 7-year-old me thought that was a bad idea but she insisted that it was fine.

          I wonder what happened to her. I hope she didn’t accidentally harm a kid in an unintentional D-cell-powered terrorist attack.

        • pewpew@feddit.it
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          4 months ago

          At least that charger had a safety feature that would not charge a battery if it was too worn