As someone who's worked with battery gauge ICs for embedded electronics, this made me cry. Just leave the damn engineer alone and USE YOUR PRODUCT PROPERLY YOU FUCKING USER!
I'm ok I'm ok, I'm calm, I'm centered, I won't blame the user for being an idiot, I'm calm, I'm centered, I won't blame the user for being an idiot, I'm calm, I'm centered, I won't blame the user for being an idiot.
Just like Marilyn Manson/Michael Jackson (the urban legend exists for both of them).
Seriously though, I don't think this would help as much as constant daily stretchings. For example, I would assume you'd have to be rather slim, otherwise your gut is in the way of the bend.
That said, according to people who have achieved it, it feels more like sucking a dick then getting your dick sucked, so just giving in into homosexual curiosity might be the easier way to experience the feeling.
I recognize why power banks can't charge and discharge simultaneously. But surely, with as cheap as integrated circuits and voltage regulators are, we can have a power bank that can be charged while it redirects some power around its cells to a device on the other side?
Sure, both would charge at half the speed. But if you only have one brick, it's better because you don't have to swap the cables halfway through. Plus, if your phone charges faster than the power bank (which it almost certainly will), you can unplug it at full charge before the power bank is done and let the bank finish- or unplug both and have a fully charged phone and a partially charged power bank.
Made even better, what if we integrated a power bank into a GaN charging brick? Plug it into the wall, use it to charge your devices every night, the smarts inside it regulate the battery with charge/discharge cycles; but then when you're ready to go somewhere you just unplug it from the wall, flip the prongs back inside, and go. Maybe you could even push a button to tell it to charge to full. It would also be a UPS of sorts, since it wouldn't know the difference between a power outage and you taking it on tour. Yeah, it would need to be kinda big and bulky when it's on the wall, but the convenience of not needing to track it down and plug it in before you go on vacation would be worth the hassle of needing to plug it into the bottom outlet on a power strip. Something about the size of a MacBook charger, but with all the high-wattage stuff swapped out for battery cells.
Is that true though? As in, is it really that dangerous? It seems that you'll dissipate power equal to the inefficiency times the nominal charging power, so something like 5V x 2A x inefficiency (inefficiency being 1-efficiency), which will probably be of order a watt.
I can use my car battery to charge itself without any issues --- I just plug the red terminal to itself, and same with the black, which is to say, a battery is always connected in a way that "charges itself."
I think the key is that the battery probably isn't really playing a big role in OOP's setup --- electricity doesn't "go through the battery," it just goes from the charging input to the power output circuits, with the additional power (due to inefficiency) being provided by the battery.
It's not even shorting it. Imagine if you took a plain battery and tried to charge itself from itself. You'd connect +ve to +ve and -ve to -ve: it'd do nothing.
I think the battery pack does clever things stepping voltages up and down: that's how it can give charge at the same 5v as it was charged itself. So in this case those circuits will be just burning off energy.
I'm not sure though --- the power output and the charging input are both regulated and (almost certainly) current limited. So I think (not positive...) that you're basically dissipating your power in the inefficiency the charging and output circuits, with this power coming from the battery.
The inefficiency should (I think...) just be the round-trip inefficiency of the charging/discharging of your power bank --- this should be way, way less than the short-circuit power dissipation.
The simplest toy model is to take a battery and try to charge itself. So you put jumpers on the + terminal and you connect those to the + terminal, and same for - (charging is + to +, NOT + to -). But this is silly because you've just attached a loop of wire to your terminals, which is equivalent to doing nothing. With charging circuits in between things get much more complicated, but I'm not sure if it goes full catastrophic short...
I'm pretty sure both directions are regulated, and the only reason it went up is some slight change in the voltage reading due to temperature or somesuch. All that I believe will happen here is that the battery, due to generating a bit of heat, will discharge itself at a safe rate.
Most banks can't charge and discharge at the same time.
If they did, worst case it heats up as it moves the energy around until it runs out due to losses or blows up.
Nothing that can go wrong really.