[Swordmaker]

Well, now, let’s do a little simple math.

Let’s say we have a 2000 mAh battery that will accept a charge current of 500 mA, and it takes 5 hours to fully charge (there are always substantial losses in the charging process.) If said battery can be charged 20x faster (ie., in 15 minutes), our charge current is up to 10 amps. That’s a MUCH bigger, more expensive charger.

Similarly, if the battery has 20x the capacity (40 Ah), given the original 5 hour charge time, again, charge current is 10 amps.

If the battery has 20x the capacity and can be fully charged in 15 minutes, then charge current is 200 amps.

Obviously, the battery banks needed to propel vehicles are MUCH larger. The recharging stations could be quite, uh, interesting. Plus, heat dissipation in both the charger and the batteries being charged would seem to be a very large concern.

My problem is the reality of what an electric cell is. . . it is a means of releasing energy by chemical change. There is an exothermic reaction if you charge it too fast as you add energy, forcing a chemical change. At one rate, the exothermic reaction is manageable, speed charging up by 20x, can they say the same? I really don't think so. I think the battery, a collection of cells, would get very HOT.

[Paul R.]

Yes, that is my point about heat in the battery being charged. I’d guess that the improvement being touted involves less heat generation as the current is pushed in, and / or less tendency to go exothermic, but, still, 20x is dumping in a LOT of energy quickly.

This can be seen in high capacity batteries being charged by “quick chargers” (ie., high current chargers) available even a few years ago. The batteries get HOT.

Internal resistance of the cells would need to be much lower too — making for high output capacity without overheating, but, if the thing ever shorts out, oh boy!

I happened to accidentally short out a plain ‘ol Alkaline cell in my pocket the other day: It left a very nice burn mark on my leg...