Adrian wrote:

Allegedly, that's going to need 1600Amp at 250v to recharge fully in 5
mins. Dunno about you, but my house has a 100A main fuse.

OK, so let's say three-phase at 415v. That's only just under 1000A.

Assuming 100% charging efficiency.

What sort of heat is the battery going to generate under that sort of
charge?

Typical 12 volt lead-acid automotive battery has an internal resistance
of 0.01 ohms. Let's be very generous and let Drivel's magic battery
have an internal resistance just a tenth of that, 0.001 ohms.

I²R gives 1600 x 1600 x 0.001 = 2,560 watts . . . hhmmmm!

--
Ian Edwards

He's not dead, he's electroencephalographically challenged.