The principle is that the speed of the current varies per unit time. The so-called home AC slow charge, is on the basis of the existing residential power supply system (using single-phase 220V or three-phase 380V), the use of 5-10kW power level charger (in fact, it is an AC to DC, the output voltage is not necessarily low), converted into DC, the car battery charge.
At present, most of the 380V chargers are fixed in public parking lots, with special lines, which can provide higher power (for example, more than 20kW)
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There is also a concentrated high voltage (10kV) introduction, converted into direct current, access to large battery packs (can use sodium sulfur batteries, vanadium batteries, etc.). This can provide a higher charging current and prevent impact on the grid when connected (of course, the support of the charging interface is required).