The charging curves of supercapacitors differ from those of batteries, primarily in the initial charging phase. A battery must undergo trickle charging and pre-charging before entering constant-current charging, whereas a supercapacitor transitions directly into constant-current charging. The supercapacitor charging process is shown in the following figure:

Different OEMs specify varying scenario configurations and charging time requirements, with typical charging times ranging from a dozen seconds to several minutes. A shorter charging time implies a larger charging current, which influences the choice of charging topology. For charging currents of a few hundred milliamperes, a linear charging topology can be selected, while switching-mode power supply topologies are preferred for currents of 1A and above.