Induction hob recommendations?

[TheCaller]

As I said earlier, I must look up what the internal circuitry does with the input voltage before it's suitable for driving the coils.

Well that took a couple of hours! Took 5 mins to discover that the coils are fed with alternating current at a frequency that seems to be anywhere between 25 - 50kHz (note kHz, not Hz). Took an age to find out what the voltage is though - eventually tracked it down & it's in the 600v region.

For a 230v appliance. it appears that the sequence is: rectify to un-smoothed DC, then invert to 600v 25kHz to feed the coils. I've skipped the control circuitry that adjusts the power levels, so that's just the basic principle.

So a battery powered induction hob is perfectly feasible - just omit the rectification stage, but the inverter has to make a much bigger voltage step up.