A battery system includes: first and second battery modules connected between first and second system terminals in parallel; and a controller controlling the first and second battery modules. The first battery module includes a first battery and a first main switch, and a first balancing switch and a first balancing resistor, which are connected to the first main switch in parallel. The second battery module includes a second battery and a second main switch, and a second balancing switch and a second balancing resistor, which are connected to the second main switch in parallel. The controller is configured to detect a first battery voltage and a second battery voltage, and when an absolute value of a difference between the first and second battery voltages is greater than a first reference value, to open the first and second main switches and to close the first and second balancing switches.

The charge control circuit includes a cell connection detection circuit monitoring a voltage between input ports to which terminals of a cell pack are connected, an overvoltage detection circuit monitoring an overvoltage of the secondary cells, a first latch circuit receiving a signal output by the cell connection detection circuit, a second latch circuit receiving a signal output by the overvoltage detection circuit, a reset circuit outputting a signal to the first latch circuit and the second latch circuit when the charge control circuit is activated, and a control circuit receiving a signal output from the second latch circuit and outputting a signal for protecting the cell pack from the overvoltage. The control circuit does not output a signal for blowing the fuse until the first latch circuit receives a detection signal of the cell connection detection circuit.

A cell formation system for lithium containing secondary batteries includes a population of formation clusters, each formation cluster includes a connector configured for connecting to a lithium containing secondary battery, a charging module connected to the connector and configured to charge the battery, a pre-lithiation module connected to the connector and configured to diffuse lithium to electrode active material layers of the battery, a discharging module connected to the connector and configured to discharge the battery, and a communication interface for communicatively coupling the formation cluster to a central controller. In response to received instructions from the central controller, the formation cluster is configured to charge the battery using the charging module, diffuse lithium to the electrode active material layers of the battery using the pre-lithiation module, and discharge the secondary battery using the discharging module after lithium has been diffused to the electrode active material layers of the battery.

A pre-lithiation module for a lithium containing secondary battery includes a switched capacitor circuit, a pre-lithiation module controller connected to the switched capacitor circuit, a battery connector for electrical connection to an electrode busbar and a counter-electrode busbar of the lithium containing secondary battery, and a pre-lithiation connector for electrical connection to an auxiliary electrode of the lithium containing secondary battery. The pre-lithiation module controller includes a processor and a memory. The memory of the pre-lithiation module controller stores instructions that program the pre-lithiation module controller to operate the switched capacitor circuit to selectively conduct a current through the auxiliary electrode to diffuse lithium to electrode active material layers of the lithium containing secondary battery.

A power unit operable to power equipment, the power unit including an electric motor, multiple removable and rechargeable battery packs, multiple switching elements, and a control unit. Each of the switching elements is connected between one of the battery packs and the electric motor and operate in one of an open position or a closed position. The control unit is operable to manage the position of the switching elements. The control unit is configured to determine whether one or more battery packs are supplying power for the electric motor, measure a voltage of each of the battery packs, determine whether each of the voltage measurements is within a predetermined value to each other, calculate a pulse width modulated (PWM) signal for each of the switching elements, assign each PWM signal to one of the switching elements, and apply each of the PWM signals to the assigned switching element.

An apparatus is provided for charging a first storage battery and a second storage battery electrically connected together in series includes a first Kelvin connection, a second Kelvin connection and a third Kelvin connection coupled to the storage batteries. At least two of the Kelvin connections are configured to charge at least one of the first and second batteries. A charging source configured to selectively couple a charge signal to a storage battery through the Kelvin connections. A switching device selectively couples the charging source and measurement circuitry to at least two of the first, second and third Kelvin connections. A microprocessor selectively controls the switching device, charges the batteries, and measures a parameter of the batteries as a function of the charging signal applied to the batteries.

A system of charging a battery pack with single charger includes a battery module, a main charging module, and a balance charging module. The battery module has a battery pack, and the battery pack has a plurality of cells in series. The main charging module has a main charger. The balance charging module has a balance charger. All the cells of the battery pack of the battery module are charged at the same time by the main charger of the main charging module. After the charging task of the main charging module is completed, the cells of the battery pack of the battery module are charged in sequence by the balance charger of the balance charging module.

A battery exchanger in which a mobile battery that has a connector is held by being accommodated or placed therein, wherein the battery exchanger has: a slot for holding the mobile battery; a connector provided to the slot in a manner allowing relative movement, the connector being connected to the connector; a through-hole provided to the slot, the connector being passed through the through-hole; and a shutter provided to the slot in a manner allowing relative movement, the shutter closing off at least a part of the through-hole.

A battery pack includes a housing, a cell group, an interface disposed on the housing so as to be connected to a charger or a power tool. The interface includes a first terminal electrically connected to a first electrode of the cell group, a second terminal electrically connected to the first electrode of the cell group, and a third terminal electrically connected to a second electrode of the cell group. The battery pack includes a first interrupt circuit disposed on a discharging loop, a second interrupt circuit disposed on a charging loop, and a control unit connected to the second interrupt circuit. The second interrupt circuit has an on state and an off stat. The control unit outputs, under a preset condition, a control signal to the second interrupt circuit such that the second interrupt circuit switches from the on state to the off state.

A battery module includes n batteries, n≥3. The n batteries are stacked in a sequence along a thickness direction of the battery, and m is defined as a round number of n/2, and the first battery and the m-th battery satisfy at least one of the following conditions: a1: a capacity of the m-th battery is greater than that of the first battery; b1: under a same state of charge, an open circuit voltage of the m-th battery is less than that of the first battery; and c1 under a same state of charge, an AC impedance of the m-th battery is less than that of the first battery.