A balancing unit is installed on a battery cell, and includes an element for measuring state parameters of the cell, a wireless communication element, making it possible to send and receive state parameters, and a wireless power transfer element.

One or more battery sub-modules are selected by obtaining at least one voltage from each battery sub-module and selecting based at least in part on the obtained voltages. The battery sub-modules are electrically connected in series in order to provide power to a primary load. Each battery sub-module includes a plurality of cells electrically connected in series and each battery sub-module further includes a battery management system that monitors the cells in that battery sub-module. Those battery management systems in the selected sub-modules are turned off so that the battery management systems in the selected sub-modules do not consume power at least temporarily from the cells in the selected sub-modules while (1) the battery sub-modules are not providing power to the primary load and (2) the battery sub-modules are not being charged.

A system includes a battery and a power management unit connected with the battery. The power management unit controls power to the battery. A spare power unit can connect with the power management unit and the battery. The power management unit stores excess charge to the spare power unit and to divert stored charge to the battery when the battery is charged less than a determined percentage.

Multi-cell battery packs can be made safer with certain features that mitigate the consequences of cell failure. Parameters of a cell are monitored to determine when the cell should be disconnected from the pack in case of a fault. The battery is reconfigured to continue operating in a safer mode. An over-charging prevention system reduces the maximum voltage that remaining battery pack can be charged to, so that the cells do not overcharge. Additional circuitry allows the disconnected cell to be periodically reconnected to the battery pack to determine if its conditions have sufficiently improved. The cells also include components for self-powering these cell functions while it is disconnected from the rest of the circuit.

A battery managing apparatus includes a battery controller configured to determine a time when a battery enters a steady state based on a charge and discharge current of the battery. The apparatus further includes a time controller configured to wake up the battery controller based on the time when the battery enters the steady state. The battery controller is configured to control the battery in response to the time controller waking up the battery controller.

A battery pack includes: a battery including at least one battery cell; a power line communicator connected to a current path to detect a first data signal; and a battery management system (BMS) to receive the first data signal from the power line communicator, and to control the battery according to the first data signal.

A battery pack receives a charging current from a charger via a power line. The battery pack includes a battery management unit and a transmitting unit. The battery management unit is coupled to a plurality of battery cells and is operable for acquiring data associated with the battery pack. The transmitting unit is coupled to the battery management unit and is operable for transmitting the data to the charger via a power line.

Embodiments of the present disclosure provide an equalization circuit, a device to be charged and a charging control method. The equalization circuit includes: a first converting unit, configured to receive a direct voltage output by a first battery cell and to convert the direct voltage output by the first battery cell into a first alternating voltage; a first resonant unit, configured to receive the first alternating voltage and to convert the first alternating voltage into a second alternating voltage in a resonant manner; a first capacitive coupling unit and a second converting unit, in which the first capacitive coupling unit is configured to couple the second alternating voltage to the second converting unit in a capacitive coupling manner, and the second converting unit is configured to convert the second alternating voltage into a first charging voltage for charging a second battery cell.

A battery balancing method and circuit for balancing the voltages between battery units with a fly capacitor. In a first time period of a switching cycle, the first battery unit is used to charge the fly capacitor or the first battery unit is used to discharge the fly capacitor, depending on which of the first battery unit and the fly capacitor having a larger voltage value; and in a second time period of the switching cycle, the second battery unit is used to charge the fly capacitor or the second battery unit is used to discharge the fly capacitor, depending on which of the second battery unit and the fly capacitor having a larger voltage value

Disclosed is a battery balancing apparatus and method. The battery balancing apparatus includes a plurality of balancing circuits, each balancing circuit is connected in parallel to a respective battery cell among a plurality of battery cells and the plurality of balancing circuits are connected in series to each other, in one-to-one relationship; and a control unit operably coupled to each balancing circuit. The control unit selects at least one of the plurality of battery cells as a balancing target, based on a SOC of each battery cell, and outputs an enable signal and a balancing message to each balancing circuit connected to each battery cell selected as the balancing target. Each balancing circuit transmits a first wireless signal and a second wireless signal corresponding to the balancing message by using electric energy stored in each battery cell, when the enable signal is received by each balancing circuit.