That goes for any sufficiently dense energy storage system, including most batteries. Imagine someone accidentally shorted out a car battery with something that can withstand a few thousand amps. (Come to think of it, a room temperature superconductor would do nicely for that purpose...).
Well, for starters, batteries have their own internal resistance. Not a whole lot, but enough that whether you short out with copper wire or superconductor, the effect would be the same.
> Well, for starters, batteries have their own internal resistance.
Indeed they do.
> Not a whole lot, but enough that whether you short out with copper wire or superconductor, the effect would be the same.
Not necessarily, assuming a charged battery in many cases with a copper wire the wire will simply heat up to the point of evaporation and then break the circuit as it sprays molten copper bits all over the place. Some heat will be generated in the battery as well. Watch people mess up with starter cables for some ideas on how this tends to go (and do so from a distance...).
Using a massive copper connector that you some how instantly put across the terminal and manage to keep there would indeed make the balance of the resistance shift to the guts of the battery, which would heat up faster than that that energy can be shed and hence in all likelihood (violently) explode. Besides bits of molten lead and zinc for a car battery you now also have the joy of having to deal with spraying acid. Which depending on the state of charge of the battery can be really nasty stuff.
With a superconductor there would be no chance of the conductor evaporating first, there isn't any work done in the superconductor so it will stay cold, an explosion of the battery would be all but guaranteed.
Keep in mind that a superconducting energy storage device is kind of the opposite of a battery. An idle battery at full charge has some voltage and zero current, and it’s perfectly happy to stay like that.
An idle superconducting energy storage at full “charge” is not carrying a charge at all — it’s carrying a current. If you cut the wire (or blow a fuse), V = L dI/dt will generate an arbitrarily high voltage to keep that current flowing.
I imagine one would need some spark gaps and/or capacitors to limit the voltage.
It's a coil. You can just place another inductor around it and increase / decrease that current at will. This is how Kamerlingh Onnes injected current into his superconducting media during the original experiments and that is a two-way street.
I did something similar once with a high power lowish voltage battery array - my soldering iron's shroud literally vaporized with a deafening bang before even triggering the fuse.
Ri of those is typically 1 Ohm or thereabouts, which at 500 A develops 500W in the battery itself and a large multiple of that in your 'load' (in this case your soldering iron :) ).
When working with large battery arrays I use tools that are taped in all the way except for the business end, just in case. All you need to do is drop a wrench in the wrong spot and it's party time.
Not 1Ohm, in my case the array had an internal resistance of 15 milliOhms, which is way more fun. Though I imagine the BMS and fuse were relatively effective resistors in that situation too.
Agreed about taped tools, I figured that one out right after replacing the fuse :)
A BMS typically has a small shunt that helps to figure out the state of charge as well as a large transistor in series with the current to allow switching the battery in and out of circuit.
Yes, I had an additional fuse in series, what I was referring to is that the BMS's own internal resistance is larger than that of the battery pack. Indeed in an overcurrent situation you can't rely on the MOSFET not to fail short.
