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US 7,609,031 B2Granted
Method for balancing lithium secondary cells and modules
AssigneeSouthwest Electronic Energy Corporation
InventorsClaude Leonard Benckenstein, David Allen White
Life of this patent
Estimating the term…
Abstract
A battery pack control module for balancing a plurality of lithium secondary cells or groups of lithium secondary cells connected in series and method of use.
Claims25
A battery pack control module for balancing a plurality of lithium secondary cells or groups of lithium secondary cells connected in series, wherein the battery pack control module comprises:
- a controller assembly;
- a disconnect circuit comprising a charge switch and a discharge switch, wherein the disconnect circuit engages the controller assembly and the plurality of lithium secondary cells or groups of lithium secondary cells connected in series;
- a pack sensing circuit connected to the controller assembly and the plurality of lithium secondary cells or groups of lithium secondary cells connected in series, wherein the pack sensing circuit comprises:
- a temperature measuring device;
- a current measuring device;
- and
- a cell voltage measuring device;
- at least one balancing circuit connected between the plurality of lithium secondary cells or groups of lithium secondary cells connected in series and the controller assembly, wherein each balancing circuit comprises:
- a shunt resistor connected to a bypass switch;
- a power source for charging the plurality of lithium secondary cells or groups of lithium secondary cells further connected to the controller assembly;
- a current limiting resistor connected to the power source for limiting current from the plurality of lithium secondary cells or groups of lithium secondary cells connected in series while charging;
- at least one configuration table containing cell specifications of the lithium secondary cells disposed in configuration memory connected to the controller assembly;
- a protective diode connected to the plurality of lithium secondary cells or groups of lithium secondary cells connected in series and to the at least one disconnect circuit, and the protective diode prevents excessive voltage from developing across the controller assembly;
- computer instructions within the controller assembly for instructing the controller assembly to monitor the state of charge for the plurality of lithium secondary cells or groups of lithium secondary cells connected in series;
- computer instructions within the controller assembly for instructing the controller assembly to control the disconnect circuit in conjunction with control of the balancing circuit and apply voltage from the power source to the charge switch or discharge switch from a lithium secondary cell or groups of lithium secondary cells when a predetermined state of charge has not been reached or is exceeded;
- and
- computer instructions within the controller assembly for instructing the controller assembly to measure the state of charge for each lithium secondary cells after each application of voltage and if a predetermined state of charge is reached for each lithium secondary cell actuate at least a partial discharge of one or more lithium secondary cells simultaneously, enabling simultaneous discharge of one or more lithium secondary cells while one or more lithium secondary cells is charging, discharging, quiescent, or is in storage.
14 more elements
A method for extending power duration for lithium secondary cells or groups of lithium secondary cells connected in series, or connected in parallel and then in series, comprising the steps of:
- monitoring and measuring parameters for lithium secondary cells or groups of lithium secondary cells connected in parallel, or are further connected in series, to determine a state of charge for the lithium secondary cells or groups of lithium secondary cells;
- limiting current from the plurality of lithium secondary cells or groups of lithium secondary cells connected in parallel, or are further connected in series, to determine a state of charge for lithium secondary cells or groups of lithium secondary cells;
- using protective diode connected to the plurality of lithium secondary cells or groups of lithium secondary cells connected in series and to the at least one disconnect circuit, and the protective diode prevents excessive voltage from developing across the controller assembly;
- removing at least a portion of a charge from at least one of the lithium secondary cells or groups of lithium secondary cells to achieve a balanced state of charge for the lithium secondary cells connected in series, or groups of lithium secondary cells connected in series, in a discharge phase, a charge phase, a quiescent phase, and a storage phase using a digital controller to execute computer instructions, wherein the computer instructions instruct a processor comprise the steps of:
- monitor the state of charge for the lithium secondary cells or groups of lithium secondary cells;
- control a disconnect circuit connected to a controller assembly while controlling a balancing circuit connected to the lithium secondary cells or groups of lithium secondary cells to apply voltage from a power source to a charge switch that is part of the disconnect circuit;
- or discharge voltage from a lithium secondary cell or groups of lithium secondary cells when a predetermined state of charge has not been reach or a predetermined state of charge has been exceeded;
- and measure a state of charge for each lithium secondary cell or groups of lithium secondary cells after each application of voltage and prevent application of voltage and if a predetermined state of charge is reached for each cell or groups of cells enabling at least partial discharge of one or more lithium secondary cells or groups of lithium secondary cell simultaneously while one or more lithium secondary cells or groups of lithium secondary cells is charging.
5 more elements
Dependencies are inferred from the claim text.