A system comprising a high voltage (HV) bank section using energy storage devices arranged into one or more banks, an inductive device coupling the HV bank to a service voltage (SV) bank section and load through a charging circuit charging the SV bank from a more fully charged bank until the charging bank is depleted, and a switch switching, from the depleted bank to the other bank to charge the SV bank. The charging circuit then charging the depleted bank by a power supply as the other HV bank charges the SV bank. A supervisory controller controls the switch to repeat discharging and charging between the two banks for a defined period. The energy storage devices may be supercapacitors capable of storing energy on the order of 1 to 10 MegaJoules, and the inductive device may be a high-inductance, toroidal multifilar inductor.