At home, most people in the USA and Canada would have nominal 240vac for their EVSE. A commercial location is more likely to have 208vac from a leg of the 3-phase transformer and many Euro countries tend to be closer to 220vac. 240vac*32A=7.6Kw (more than the i3 can handle); 208*32A=6.6Kw, which is the upper limit shown for many commercial EVSE's. Keep in mind, it's not only the amps, it's how hard they are being pushed (by the voltage) that determines the ultimate amount of power being used. The charging circuits in the i3 are current limited (as announced by the EVSE). IOW, the max current the i3 will draw is determined by it's internal logic and by what the EVSE announces it has...if that is 30A, as the voltage changes, the power changes. Another thing to consider, the Euro standard for charging an EV is based on peak current, the USA standard is max continuous, and for all practical purposes, 30A USA is equivalent to 32A peak Euro spec EVSE's.
Home service voltages can vary +/- 10% easily, so that will affect the watts available. I'm regularly seeing about 245vac, but you may not be getting much more than 220vac which, with the same 32A peak limit would be a max of 7Kw and a 30A continuous would be 6.6Kw. In a brown-out situation, the voltage could drop even more, and if you live where the transformer is overloaded, your output could be marginal as well.
So, don't blame the car (well, it could be, but I doubt it), without knowing what the supply voltage actually being applied, the output specification of an EVSE is only representing a maximum theoretical amount...IOW, you may not have ideal conditions, and it would be 'normal' to get less. If the pilot signal out of the EVSE is slightly off, it might be announcing a lower capability as well. The car won't try to use more than the EVSE announces it has.
