A circuit enabling precharge, active discharge and battery balancing operations in a single subcircuit is described. According to one or more embodiments, a circuit is provided comprising a first battery comprising a positive terminal coupled to a positive transmission line and a negative terminal coupled to a common node, wherein the positive transmission line comprises a first contactor, a second battery comprising a positive terminal coupled to the common node and a negative terminal coupled to a negative transmission line, wherein the negative transmission line comprises a second contactor, and a subcircuit coupled to the common node, to the positive transmission line, and to the negative transmission line.

Improved systems and methods for balancing a state of charge (SOC) of a plurality of batteries are disclosed. For example, a system may include multiple battery strings connected in parallel to one another through a common bus. Each battery string may include a power converter and multiple battery modules connected in series. The power converter may be configured to regulate the combined power output of the battery modules. Each battery module may include multiple relays that may be controlled to discharge, charge, and/or bypass that battery module. Collectively, the power converters of the battery strings and the relays of the battery modules may be controlled to balance the battery strings with one another and to balance the battery modules within each of the battery strings.

There is fear that some battery cells among battery cells which are serially connected may consume electric power all the time, thereby causing expansion of unbalance in voltage of the battery cells and hindering electric discharge of a battery system. When a second battery has a sufficient voltage, an electric current control board supplies operating power to a battery control unit and a relay via an external minus line and an external plus line. On the other hand, when the voltage of the second battery has decreased, the electric current control board supplies the operating power from a first battery to the battery control unit and the relay via an internal minus line and an internal plus line. A first electric current control unit and a second electric current control unit control the supply of the operating power according to, for example, the decrease in voltage of the second battery.

A voltage balancing circuit for capacitor banks or voltage cells connected in series. The circuit includes a DC-link with at least two capacitors or voltage cells connected in series and at least two emitter follower balancing circuits connected in parallel. At least one emitter resistor is provided between the emitter of each emitter follower balancing circuit and the mid-point of the DC-link. The gate emitter voltage applied to each emitter follower balancing circuit may be equal to its common gate voltage minus the voltage drop on the corresponding emitter resistor. The invention is also directed at a variable frequency drive for driving an electric motor or a power converter, having a corresponding voltage balancing circuit.

The techniques disclosed herein may achieve efficient regulation of power delivered from one or more batteries to a circuit or system with a power control device that has two or more operating modes. In a first operating mode, the power control device may select a first power circuit to deliver power to a system load with a first quiescent current, while in a second operating mode the power control device may select at least one additional power circuit to deliver power to the system load with a second quiescent current. The first quiescent current is significantly less than the second quiescent current such that operation of the first power circuit corresponds to a lower power mode than the additional power circuits. An ideal diode circuit may be configured to selectively couple the outputs of each of the power circuits to the system load.

A system for balancing and converting voltage output from photovoltaic modules includes a set of solar substrings, a power conversion circuit, and a controller. The power conversion circuit includes: a set of windings coupled in series and arranged in parallel to the set of solar substrings; a set of switches coupled in parallel and interposed between the set of solar substrings and the set of windings; and an output switch coupled in series to a first switch, in the set of switches, and an output capacitor. The controller is configured to: oscillate states of the set of switches and the output switch at a first duty cycle; balance voltages output from the set of solar substrings across the set of windings to a nominal output voltage; and modify the nominal output voltage to a target voltage directed to the target load based on the first duty cycle.

A system can include a battery pack with battery cell sections connected in series, where each of the battery cell sections includes a battery cell and a bypass switch. The system can also include a control circuit. The control circuit can determine a capacity of a particular battery cell in a particular battery cell section, determine that the capacity of the particular battery cell is less than a predefined threshold, and in response, execute a bypass sequence for the particular battery cell. The bypass sequence can involve determining a bypass period for which to bypass the particular battery cell based on the capacity of the particular battery cell, and transmitting a bypass signal to a drive circuit. The drive circuit can receive the bypass signal and responsively operate the bypass switch of the particular battery cell section to bypass the particular battery cell for the bypass period.

The present disclosure relates to a battery cell balancing device and method, and a battery management system, and the technical problem to be solved is to provide a mechanism capable of increasing a service lifespan of the battery pack by allowing a balancing function to be maximally used in a range in which a cell voltage measurement error may be compensated for even when an abnormality has occurred in an internal circuit of the battery management system (BMS). To this end, the present disclosure provides a configuration of determining whether an abnormality occurs in an RC circuit based on a cell voltage of a battery cell measured through the RC circuit of the BMS, and controlling a switching time of a balancing switch to compensate for a cell voltage measurement error caused by the abnormality in the RC circuit.

A battery cell system includes multiple battery cells and a control circuit. The battery cells include an internal cell resistance. The control circuit is configured to detect when a charge level of a first battery cell of the battery system is greater than a charge level of a second battery cell of the battery system; and activate an internal cell resistance of the first battery cell to reduce the charge level of the first battery cell and deactivate the internal cell resistance when the charge level of the first battery cell is within a specified threshold charge level of the second battery cell.

A programmable battery pack including a switch arrangement module having at least one rechargeable battery with and at least one single pole single throw (SPST) switch, a system power supply having at least one linear regulator and at least one single pole single throw (SPST) switch, at least one controller module having a micro-controller executing a pre-programmed firmware, and an external power supply.