A battery pack charger including a housing, a charging circuit, a first charger terminal and a second charger terminal connected to the charging circuit and configured for providing charging power to a battery pack, and a controller. The controller includes a processor and a memory. The controller is configured to charge the battery pack with a constant power charge, switch to a constant voltage charge when a voltage of the battery pack reaches a predetermined threshold, and charge the battery pack with the constant voltage charge.

A method for managing a plurality of batteries that are electrically coupled together includes (1) monitoring respective voltages of the plurality of batteries and (2) in response to a respective voltage of a first battery of the plurality of batteries reaching a first threshold value at a first time, reducing a charge or discharge rate of the first battery, relative to at least a second battery of the plurality of batteries. Charge and discharge rates may be adaptively managed such that each battery reaches the first threshold value at substantially the same time.

Methods and systems for charging a battery utilizing a negotiable power supply in which the power supply and a component of a charge circuit negotiate a level of power are disclosed. A charge circuit may include a controller to communicate with the negotiable power supply to request a power signal comprising a voltage and a maximum current, which may then be provided by the negotiable power supply. A voltage value and/or maximum current value of the negotiated power signal may be provided as parameters to a model of one or more components of a charge signal shaping circuit. The circuit model may utilize the provided power parameters when modeling one or more charge circuit components to generate an accurate model of the charge circuit and used to control a charge circuit to provide power to recharge the battery that limits a power level that may damage the battery during charging.

The present disclosure includes a method of charging a battery. In one embodiment, the method comprises receiving, in a battery charging circuit on an electronic device, an input voltage having a first voltage value from an external power source. The battery charger is configured to produce a charge current having a first current value into the battery. The input current limit and/or duty cycle of the charger is monitored. Control signals may be generated to increase the first voltage value of the input voltage if either (i) the input current limit is activated or (ii) the duty cycle reaches a maximum duty cycle. The charger also receives signals indicating a temperature inside the electronic device and generates control signals to decrease the value of the input voltage when the temperature increases above a threshold temperature.

Systems and methods for wireless power transmission based on object identification are provided. A radio frequency wireless power transmitter is in communication with a video camera for capturing image data (e.g., a visual pattern) of at least a portion of a transmission field of the radio frequency wireless power transmitter. A processor of the radio frequency wireless power transmitter is configured to identify an object when the visual pattern matches a pre-stored visual pattern representing the object, and control transmission of one or more radio frequency power transmission waves to a receiving electronic device based on a location of the identified object, wherein the receiving electronic device uses the one or more radio frequency power transmission waves to power or to charge the receiving electronic device.

A charger for impulsed charging of a battery includes first and second charging contacts configured to receive a battery to be charged, a DC power input having first and second terminals, and an inductor having first and second ends. The first end is selectively conductively connectable to the first terminal and the second charging contact. The second end is selectively conductively connectable to the first charging contact and the second terminal. A switch is between the second end and the second terminal such that with the switch in a first configuration, the inductor is connected across the DC power input to enable magnetic energization of the inductor, and in a second configuration, the inductor is disconnected from the DC power input and connected across the charging contacts to enable magnetic energy in the inductor to discharge to the battery. The switch is alternated between configurations during charging of the battery.

A portable power bank for charging a rechargeable device is described, and a dynamic charging efficiency is monitored while the power bank is charging the rechargeable device. Particularly, instantaneous power output of a battery of the power bank is compared to power received by a battery of the rechargeable device to determine efficiency. The charging of the rechargeable device by the power bank is interrupted and/or resumed based upon the charging efficiency at any given time, thereby preventing inefficient use of the power bank.

Devices, systems, and methods may use a low current power source to charge an intermediate storage unit, providing sufficient electric power to perform various device functions. A voltage of the intermediate storage unit may be monitored using a voltage monitoring circuit, and a primary storage unit may be charged using current from the intermediate storage unit when the voltage of the intermediate storage unit meets a threshold.

A battery charging method includes during charging of a battery, upon determining that a state of charge (SOC) of the battery reaches an SOC range, adjusting, within a range from a minimum boundary value of the SOC range to a set SOC, a charge rate of the battery from a first charge rate down to a second charge rate; and adjusting, within a range from the set SOC to a maximum boundary value of the first SOC range, the charge rate of the battery from the second charge rate up to the first charge rate or a third charge rate.

A power storage device (4) includes a power storage unit (1211) including a plurality of cells, and a BMU (1212) configured to control the power storage unit (1211). The BMU (1212) includes an upper limit power acquisition unit (23) configured to acquire, based on a SOC and a temperature of the power storage unit (1211), an upper limit power that is an upper limit of a power output from the power storage unit (1211) or a power input to the power storage unit (1211).