Cell balancing circuitry for balancing a set of cells, the cell balancing circuitry comprising: a switch network configured for coupling to the cells; a set of capacitors coupled in parallel between the switch network and a common node; and detection circuitry configured to detect a fault in a capacitor of the set of capacitors based on a voltage at the common node.

A cell balancing system for balancing a set of series-connected cells, the cell balancing system comprising first balancer circuitry and second balancer circuitry. The first balancer circuitry comprises a first set of capacitors and a first switch network. The first switch network is controllable such that in operation of the cell balancing system: during a first phase of operation of the first balancer circuitry, a capacitor of the first set of capacitors is coupled to a first cell of the set of series-connected cells; and during a second phase of operation of the first balancer circuitry, the capacitor of the first set of capacitors is coupled to a second cell of the set of series-connected cells. The second balancer circuitry comprises a second set of capacitors and a second switch network. The second switch network is controllable such that in operation of the cell balancing system: during a first phase of operation of the second balancer circuitry, a capacitor of the second set of capacitors is coupled to a first subset of cells of the set of series-connected cells, the first subset comprising two or more of the set of series-connected cells; and during a second phase of operation of the second balancer circuitry, the capacitor of the second set of capacitors is coupled to a second subset of cells of the set of series-connected cells, different than the first subset, the second subset comprising two or more of the set of series-connected cells.

A power supplying system for supplying power in an electronic device includes rechargeable batteries coupled to a functional block of the electronic device. The rechargeable batteries include a first battery and a second battery. In a normal mode, the first battery and the second battery are connected in parallel between a system voltage supplying node and a ground node, in a first state of a charging mode, the first battery and the second battery are connected in serial between a charge input node and the ground node with a first terminal of the second battery being connected to the system voltage supplying node, and in a second state of the charging mode, the first battery and the second battery are connected in serial between the charge input node and the ground node with a first terminal of the first battery being connected to the system voltage supplying node.

An energy storage apparatus includes: a plurality of energy storage devices connected in series; a voltage detection unit that detects voltages of the plurality of energy storage devices; a discharge circuit that discharges the energy storage devices; and a control unit. The energy storage devices include lithium ion cells. The plurality of energy storage devices is chargeable by an external charger for a lead-acid battery, wherein a charge voltage per cell of the external charger for the lead-acid battery is higher than a maximum voltage of the energy storage device, and wherein the control unit discharges only an energy storage device having a highest voltage out of the plurality of energy storage devices when the plurality of energy storage devices is charged by a charger.

A method and system for AC battery operation. In one embodiment, the method comprises determining, at a battery management unit (BMU) coupled to an AC battery comprising a power converter and a battery that is rechargeable, a bias control voltage that indicates a state of a charge process of the AC battery; and coupling, by a bias control module of the BMU, the bias control voltage to the power converting for communicating the state of the charge process to and from the BMU and the power converter.

An energy storage apparatus includes: a plurality of energy storage devices connected in series; a voltage detection unit that detects voltages of the plurality of energy storage devices; a discharge circuit that discharges the energy storage devices; and a control unit. The energy storage devices include lithium ion cells. The plurality of energy storage devices is chargeable by an external charger for a lead-acid battery, wherein a charge voltage per cell of the external charger for the lead-acid battery is higher than a maximum voltage of the energy storage device, and wherein the control unit discharges only an energy storage device having a highest voltage out of the plurality of energy storage devices when the plurality of energy storage devices is charged by a charger.

A power supply charging system comprising: a) a first power cell having electrical energy stored therein; b) a second power cell having electrical energy stored therein, wherein the first power cell and the second power cell are adapted to not be in a discharging mode or a charging mode simultaneously; c) a third power cell in electrical communication with the first power cell and the second power cell, wherein the third power cell is adapted to operably supply power to the first power cell when in the charging mode or the second power cell when in the charging mode; and d) a control system which is adapted to alternate the power being supplied from the third power cell to the first power cell while in the charging mode and the second power cell which in the charging mode based on an occurrence of a pre-determined condition.

A power management and selection system for a class 8 tractor trailer, directs excess solar and vehicular charge capacity to an auxiliary load by measuring available charge capacity from a reefer power system including a reefer battery, solar panel and charge controller for moderating solar power to the reefer batter, and measuring available charge capacity from a cab vehicle power system including a propulsion system battery and alternator. Charge logic, in a selector configured for switching charge capacity to the auxiliary load, determines which of the reefer power system and cab vehicle power system has the most potential excess charge capacity, and directs the determined excess charge capacity to the auxiliary load, while the measured available charge capacity remains sufficient for powering the respective reefer power system or cab vehicle power system.

A controller discharges a traction battery according to power limits defined by output that is indicative of a state of charge of the traction battery and is updated by a bar delta filter according to a balancing current. The balancing current is associated with each cell of a string of series connected cells of the traction battery and represents a deviation of an estimated current through the cell from a total current of the string.

Battery management circuits include a first charging channel, a Cuk circuit, and a communication control circuit. A battery is charged through the first charging channel based on charging voltage and/or charging current provided by a power supply device. The battery includes a first cell and a second cell coupled in series. The communication control circuit is configured to communicate with the power supply device, to make magnitude of the charging voltage and/or charging current provided by the power supply device match a present charging stage of the battery, and the communication control circuit is further configured to send a drive signal to the Cuk circuit to drive the Cuk circuit to work, to make energy of the first cell and the second cell be transferred through the Cuk circuit to balance voltage of the first cell and voltage of the second cell.