an energy storage string formed by a plurality of rechargeable cells connected in series via electrical connectors, and wherein said energy storage string has a positive string terminal at a first end and a negative string terminal at a second end,

an energy management device comprising a master control unit and at least a first local control unit associated to a first rechargeable cell of said plurality of rechargeable cells, and

wherein said master control unit comprises

a storage string connecting circuit electrically connecting said positive string terminal with said negative string terminal,

a master AC signal generator and

a master AC signal receiver,

a cell connecting circuit electrically connecting a positive and a negative cell terminal of said first rechargeable cell,

a local AC signal generator and

a local AC signal receiver, and

wherein said storage string connecting circuit comprises a first capacitor device, and wherein said first capacitor device and said energy storage string are forming part of a first closed-loop LC-circuit, and

wherein said cell connecting circuit comprises a second capacitor device, and wherein said second capacitor device and said first rechargeable cell are forming part of a second closed-loop LC-circuit, and

wherein said master AC signal generator is adapted for transmitting power to said local control unit by supplying a sequence of first AC pulses to said first closed-loop LC-circuit, and wherein said local AC signal receiver is configured for detecting the sequence of first AC pulses in said second closed-loop LC-circuit following propagation of the sequence of first AC pulses from the first to the second closed-loop LC-circuit, and rectifying the sequence of first AC pulses detected, thereby generating a first DC current for charging a first capacitor tank of said first local control unit.