Fast charge is an emergency charging method, using DC charging, the DC charging voltage is generally greater than the battery voltage, the need to convert alternating current into direct current through the rectifier device, the power battery pack voltage resistance and protection put forward higher requirements; The charging current is large, ten times or even dozens of times that of conventional charging current.
Slow charge generally refers to the charging in the 220V AC socket of the home, because the battery can not accept AC charging. Therefore, it first converts 220V AC to DC and then boosts the charging voltage of the battery, such as 500V DC, and then charges the battery with the 500V DC. Since the general household 220V AC socket is 10A and 16A, for safety reasons, the charging current of slow charge is generally less than 10A, according to the standard calculation of 10A, the maximum charging power of slow charge is about P=UI=220V*10A=2.2KW. Since 16.25KW is much larger than 2.2KW, we can find that fast charging is much, much faster than slow charging.