Sequential power discharge for batteries in a power system

A power discharging system comprising a plurality of batteries and a plurality of control switches, wherein a first one of the plurality of control switches comprises:

• an enable input port to receive an enable input signal;
• a control output port to assert a control output signal;
• a power input port;
• a power output port;
• a power transfer device;
• a comparison device adapted to compare an external voltage with a reference voltage to generate a comparison output;
• a switching control comprising a 1:2 demultiplexing logic having a demultiplex input coupled to the enable input signal and a demultiplex select signal coupled to the comparison output, wherein
• when the enable input signal is asserted, the demultiplex input is forwarded by the 1:2 demultiplexing logic to a first demultiplex output port to enable the power transfer device to transfer an input power at the power input port received from a first battery associated with the first control switch to the power output port when the comparison output is asserted, and
• the demultiplex input is forwarded by the 1:2 demultiplexing logic to a second demultiplex output port to assert the control output signal coupled to an enable input port as an enable input signal to enable a second one of the plurality of control switches to transfer power received from a second battery to a power output port of the second control switch when the demultiplex select signal is de-asserted and when the second battery being associated with the second control switch has sufficient energy for output;
• and
• the control output port of the first control switch being linked to an enable input port of the second control switch thereby forming a control chain to control power switching of associated batteries in the power discharging system.

A power system comprising a plurality of batteries, a plurality of battery protection devices each coupled to a different one of the plurality batteries, and a plurality of control switches each coupled to a different one of the plurality of battery protection devices, wherein

• an output power of a kth battery in the plurality of batteries being coupled to an input port of a kth battery protection device in the plurality of battery protection devices, and
• an output port of the kth protection device being coupled to a power input of a kth control switch in the plurality of control switches;
• wherein each battery protection device comprises:
• a key-on switch which is caused to open when the power system is switched off and is caused to close when the power system is switched on, and
• a conjunction switch in serial connection with the key-on switch wherein the conjunction switch is caused to close when the power system is switched off and is caused to open when voltage in the conjunction switch's associated battery is detected being less than a predefined value.