A secondary aggregate battery with spatial separation of operation temperatures is provided, including: a housing, wherein a plurality of secondary battery packs and a charge balancing system connected to the secondary battery packs are disposed in the housing. The charge balancing system includes a battery state detection unit and a heat dissipation component. The housing includes a heat dissipation chamber and an accommodation chamber separated by a partition. The heat dissipation chamber accommodates the heat dissipation component, and the accommodation chamber accommodates the secondary battery packs and the battery state detection unit such that the temperature of the heat dissipation component is isolated by the independent chamber to prevent the operation temperature of the heat dissipation component affects the normal operation of the secondary battery packs.

Techniques are described for monitoring the degradation of electrochemical cells. A battery monitoring system monitors, for each of one or more cells of a plurality of cells in a battery, an amount of mechanical deformation using one or more measuring devices. The battery monitoring system determines a number of cells of the plurality of one or more monitored cells for which the monitored amount of mechanical deformation exceeds a deformation threshold. The battery monitoring system determines whether the determined number of cells exceeds a threshold number of cells with an amount of mechanical deformation exceeding the deformation threshold. Responsive to determining the determined number of cells exceeds the threshold number of cells, the battery monitoring system sends a notification that the battery is degraded beyond an acceptable limit.

Techniques are described for monitoring the degradation of electrochemical cells. A battery monitoring system monitors, for each of one or more cells of a plurality of cells in a battery, an amount of mechanical deformation using one or more measuring devices. The battery monitoring system determines a number of cells of the plurality of one or more monitored cells for which the monitored amount of mechanical deformation exceeds a deformation threshold. The battery monitoring system determines whether the determined number of cells exceeds a threshold number of cells with an amount of mechanical deformation exceeding the deformation threshold. Responsive to determining the determined number of cells exceeds the threshold number of cells, the battery monitoring system sends a notification that the battery is degraded beyond an acceptable limit.

A battery management circuit, a battery protection circuit, a power storage device, a semiconductor device, a vehicle, and an electronic device, or the like with a novel structure, a low power consumption structure, or a highly integrated structure is provided. The semiconductor device includes a first transistor comprising a first conductor and a first semiconductor over the first conductor, a first insulator over the first transistor, a second conductor provided in an opening of the first insulator, a second transistor over the first insulator, and a third conductor over the second transistor. The first conductor has a function of one of a source electrode and a drain electrode of the first transistor. The first semiconductor and the second conductor overlap each other. The second conductor and the third conductor overlap each other. The third conductor and the second transistor overlap each other. The first semiconductor and the second transistor are electrically connected to each other through the second conductor and the third conductor.

A battery management circuit, a battery protection circuit, a power storage device, a semiconductor device, a vehicle, and an electronic device, or the like with a novel structure, a low power consumption structure, or a highly integrated structure is provided. The semiconductor device includes a first transistor comprising a first conductor and a first semiconductor over the first conductor, a first insulator over the first transistor, a second conductor provided in an opening of the first insulator, a second transistor over the first insulator, and a third conductor over the second transistor. The first conductor has a function of one of a source electrode and a drain electrode of the first transistor. The first semiconductor and the second conductor overlap each other. The second conductor and the third conductor overlap each other. The third conductor and the second transistor overlap each other. The first semiconductor and the second transistor are electrically connected to each other through the second conductor and the third conductor.

A bus bar module includes a bus bar electrically connect electrode terminals respectively included in a plurality of battery cells, and a detection conductor electrically connected to the bus bar. The bus bar includes: a pair of electrode joining parts respectively joined to the different electrode terminals; a coupling part coupling the pair of electrode joining parts to each other, and capable of being cut between the pair of electrode joining parts where the pair of electrode joining parts is respectively joined to the electrode terminals; and a pair of rejoinable parts respectively extending from the pair of electrode joining parts. The electrode joining parts and the coupling part constitute a conductive connection part for primary use disposed across the different electrode terminals to electrically connect the different electrode terminals to each other.

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.

An assembly is provided that may include a battery, and an end cap mechanically and electrically coupled to the battery. The end cap may contain an electrical connector with at least one electric cable configured to supply current to at least one operating system electrically coupled to the battery. The end cap may also contain at least one electronic board coupled to the battery, and may be configured to detach from the battery to provide access to the electrical connector and the electronic board.

An assembly is provided that may include a battery, and an end cap mechanically and electrically coupled to the battery. The end cap may contain an electrical connector with at least one electric cable configured to supply current to at least one operating system electrically coupled to the battery. The end cap may also contain at least one electronic board coupled to the battery, and may be configured to detach from the battery to provide access to the electrical connector and the electronic board.

A battery module includes a battery cell, and the battery cell includes a battery cell body, a first tab, a second tab, and a third tab. The first tab, the second tab, and the third tab are separately electrically connected to the battery cell body. The first tab and the third tab have a first polarity, and the second tab has a second polarity. Working together, the second tab and the first tab are capable of inputting a voltage and a current to the battery cell body or capable of outputting a voltage and a current from the battery cell body. Working together, the second tab and the third tab are capable of inputting a voltage and a current to the battery cell body or capable of outputting a voltage and a current from the battery cell body. The first polarity is different from the second polarity.