A series-parallel battery system includes: a switch (1), a series-parallel battery (2) and a charge and discharge management circuit (3). The series-parallel battery (2) includes a battery combination management circuit (23) and at least two batteries connected to each other. The battery combination management circuit (23) is connected to the batteries. One battery in the series-parallel battery (2) includes a second battery cell (22) and a third protection circuit (26). Other batteries in the series-parallel battery (2) include a first battery cell (21), a first protection circuit (24) and a second protection circuit (25). The switch (1) is connected to the batteries. The charge and discharge management circuit (3) is connected to the battery combination management circuit (23) and used for controlling states of the switch (1), of the first protection circuit (24), and of the second protection circuit (25), so as to adjust a connection mode of the batteries.

A series-parallel battery system includes: a switch (1), a series-parallel battery (2) and a charge and discharge management circuit (3). The series-parallel battery (2) includes a battery combination management circuit (23) and at least two batteries connected to each other. The battery combination management circuit (23) is connected to the batteries. One battery in the series-parallel battery (2) includes a second battery cell (22) and a third protection circuit (26). Other batteries in the series-parallel battery (2) include a first battery cell (21), a first protection circuit (24) and a second protection circuit (25). The switch (1) is connected to the batteries. The charge and discharge management circuit (3) is connected to the battery combination management circuit (23) and used for controlling states of the switch (1), of the first protection circuit (24), and of the second protection circuit (25), so as to adjust a connection mode of the batteries.

A battery pack charger includes a battery pack interface configured to removably receive a battery pack, a charging circuit electrically connected to the battery pack interface, a discharging circuit electrically connected to the battery pack interface, and a common charging and discharging line connected to the charging circuit and the discharging circuit.

A power distribution system for an aircraft, comprising: a plurality of electric propeller units (EPUs), a first paired battery pack unit, the first paired battery pack unit, and a second paired battery pack unit. The first paired battery pack unit may include a first battery electrically connected to a second battery via a first high voltage bus. The first battery may be configured to provide power to a first set of EPUs of the plurality of EPUs, the second battery may be configured to provide power to a second set of EPUs of the plurality of EPUs, the first battery may be configured to act as a backup battery for powering the second set of EPUs, and the first high voltage bus and the second high voltage bus may be electrically separate from one another.

A power distribution system for an aircraft, comprising: a plurality of electric propeller units (EPUs), a first paired battery pack unit, the first paired battery pack unit, and a second paired battery pack unit. The first paired battery pack unit may include a first battery electrically connected to a second battery via a first high voltage bus. The first battery may be configured to provide power to a first set of EPUs of the plurality of EPUs, the second battery may be configured to provide power to a second set of EPUs of the plurality of EPUs, the first battery may be configured to act as a backup battery for powering the second set of EPUs, and the first high voltage bus and the second high voltage bus may be electrically separate from one another.

Embodiments are provided for charging system for an aircraft. The charging system may comprise a plurality of electric propeller units (EPUs), a plurality of battery packs configured to power the plurality of EPUs, a charge control unit configured to determine a target charge level for each of the plurality of battery packs, receive charge status information from each of the plurality of battery packs, and upon determining that a target charge level of at least one of the battery packs has been reached, command the at least one battery pack to disconnect from a common charging bus having a high voltage connection to a power source external to the aircraft.

Embodiments are provided for charging system for an aircraft. The charging system may comprise a plurality of electric propeller units (EPUs), a plurality of battery packs configured to power the plurality of EPUs, a charge control unit configured to determine a target charge level for each of the plurality of battery packs, receive charge status information from each of the plurality of battery packs, and upon determining that a target charge level of at least one of the battery packs has been reached, command the at least one battery pack to disconnect from a common charging bus having a high voltage connection to a power source external to the aircraft.

Provided is a control circuit suitable for power supplies with freely switchable voltages, comprising a first control circuit for freely switching the power supply voltage, a second and a third control circuits electrically connected to the first control circuit. It enables the power supply voltage to be switchably outputted at different voltage levels and realizes the conversion and protection functions of battery voltage. In other words, the present solution can meet the voltage requirements of different devices. Through precise battery management, it ensures that the battery operates safely and efficiently, thereby extending the battery's service life. In terms of user-friendliness: it provides a simple and easy-to-use voltage switching mechanism, enabling users to effortlessly select the required voltage output according to their needs. By adopting rechargeable lithium batteries to replace traditional dry batteries, it reduces the environmental pollution caused by discarded batteries while achieving energy conservation and reuse.

A cell balancing circuit and a battery device are provided. The cell balancing circuit controls cell balancing between a first battery cell that generates a first cell voltage and a second battery cell which is connected in series with the first battery cell and generates a second cell voltage. The cell balancing circuit includes: a first voltage divider circuit that outputs a first voltage divider voltage as an average voltage of the first battery cell and the second battery cell; a first differential voltage-to-current converter that discharges from the first battery cell a first cell balancing current generated according to a voltage difference obtained by subtracting the second cell voltage from the first voltage divider voltage; and a second differential voltage-to-current converter that discharges from the second battery cell a second cell balancing current generated according to the voltage difference with polarity reversed.

A vehicle includes a battery capable of charging and discharging power for traveling of the vehicle, and a BOBC including a bidirectional inverter that converts DC power of the battery into AC power, and outputting the converted AC power to an outside of the vehicle. An insulation resistance reduction detection unit senses a reduction in insulation resistance from an AC side of the bidirectional inverter to the battery. When discharging from the BOBC to the outside is performed, a processor senses a reduction in insulation resistance using the insulation resistance reduction detection unit, before connection of a relay that switches between a cut-off state and a connected state of an electric path connecting the AC side of the bidirectional inverter and the outside of the vehicle, and, when a reduction in insulation resistance is not sensed, the processor issues a command to switch the relay to the connected state.