A battery pack according to the present disclosure includes a plurality of battery blocks, the battery blocks being arrayed adjacent to each other in a stacking direction that is set in advance. After two or more of the battery blocks are replaced with multiple replacement battery blocks that have been refreshed in advance, multiple non-replacement battery blocks, among the battery blocks, that have not been replaced with the replacement battery blocks, are adjacent to each other in the stacking direction, and the replacement battery blocks are adjacent to each other in the stacking direction.

A battery pack according to the present disclosure includes a plurality of battery blocks, the battery blocks being arrayed adjacent to each other in a stacking direction that is set in advance. After two or more of the battery blocks are replaced with multiple replacement battery blocks that have been refreshed in advance, multiple non-replacement battery blocks, among the battery blocks, that have not been replaced with the replacement battery blocks, are adjacent to each other in the stacking direction, and the replacement battery blocks are adjacent to each other in the stacking direction.

A battery pack in one aspect of the present disclosure includes two or more battery blocks and a connection circuit. The connection circuit is connected to a positive terminal and a negative terminal of an electric work machine. The connection circuit connects the positive terminal and the negative terminal to a specific number of battery blocks included in the two or more battery blocks. The specific number varies depending on electrical properties of the electric work machine.

To provide an air vehicle configured to stabilize the power output of a fuel cell by securing the generated water discharge property of the fuel cell. An air vehicle, wherein the air vehicle comprises two or more fuel cells; wherein each fuel cell comprises an anode outlet manifold; and wherein each fuel cell is disposed in the air vehicle so that water discharge directions of the anode outlet manifolds are different from each other.

To provide an air vehicle configured to stabilize the power output of a fuel cell by securing the generated water discharge property of the fuel cell. An air vehicle, wherein the air vehicle comprises two or more fuel cells; wherein each fuel cell comprises an anode outlet manifold; and wherein each fuel cell is disposed in the air vehicle so that water discharge directions of the anode outlet manifolds are different from each other.

A battery system includes a plurality of battery modules each formed from a plurality of battery cells. A shared cooling structure is thermally coupled to each of the battery modules. The shared cooling structure is configured to conduct heat relative to the battery modules. A thermal interface is disposed between the battery cells of each battery module and the shared cooling structure. Each thermal interface is configured to transition from a first thermal conductivity state to a second thermal conductivity state when heat generated by the respective battery cells exceeds a threshold level. The second thermal conductivity state is lower than the first thermal conductivity state such that after one of the thermal interfaces has transitioned from the first thermal conductivity state to the second thermal conductivity state, heat transfer from the respective battery cells to the shared cooling structure is reduced.

The disclosure provides an electric energy storage device which includes four energy units with a substantially same voltage value. Each energy unit is provided with a positive electrode and a negative electrode. The electric energy storage device comprises a socket with eight independently arranged electrode terminals that are connected with the four energy units. The disclosure also provides an electric tool system using the electric energy storage device. The electric tool is provided with plugs that may be connected with the four energy units in different states, allowing the electric energy storage device to output multiple voltages.

The disclosure provides an electric energy storage device which includes four energy units with a substantially same voltage value. Each energy unit is provided with a positive electrode and a negative electrode. The electric energy storage device comprises a socket with eight independently arranged electrode terminals that are connected with the four energy units. The disclosure also provides an electric tool system using the electric energy storage device. The electric tool is provided with plugs that may be connected with the four energy units in different states, allowing the electric energy storage device to output multiple voltages.

A landing system suitable for receiving an unmanned aerial vehicle (UAV) comprises an autonomous ground vehicle (AGV). A landing surface is disposed on the AGV, and the landing system comprises a loading channel suitable for passing an object delivered by the UAV through a first loading channel opening in the landing surface. The object passes within the loading channel through to a second loading channel opening at a bottom aspect of the AGV. In this way, a UAV can land on the landing surface, and the AGV positions the object in line with a target delivery location, where the object is delivered. Aspects of the landing system comprise an electromagnet or vacuum chamber for securing the UAV to the landing surface, thereby enhancing stability of the UAV during movement of the landing system.

A power tool system includes a first and second power tools with different rated-voltages and a battery pack supplying power to the corresponding power tool. The battery pack has a battery module with two battery cell groups and a female connector having four conductive terminals respectively connected to positive and negative electrodes of two battery cell groups. The female connector has a converter switching the connection of two battery cell groups between parallel connected state to isolated connected state through connecting or disconnecting two conductive terminals with same polarity together. The first power tool includes a first male connector connected to the female connector to connect two battery cell groups in series through connecting two conductive terminals with different polarities together. The second power tool has a second male connector coupled to the female connector to connect two battery cell groups in parallel through connecting two conductive terminals with same polarity together.