# US 2013/0154567 A1 · Balancing Discharge in Parallel Battery Configurations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154567 A1 - Document ID: US20130154567A1 - Status: Published application - Kind: A1 - Application number: 13/706,537 - Filed: 2012-12-06 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Electrochem Solutions, Inc. - Inventors: Brian Robert Peterson; Jon Carroll; Arden Phillip Johnson - Web page: https://patentgrep.com/patent/US20130154567A1 ## CPC - H02J 7/52: for charge balancing, e.g. equalisation of charge between batteries - H02J 7/585: {Sequential battery discharge in systems with a plurality of batteries} - H02J 7/855: {with circuits adapted for supplying loads from the battery} - H02J 2105/30: the load networks being external to vehicles, i.e. exchanging power with vehicles - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An apparatus balances a discharge in parallel battery configuration by having a battery pack (a) with a first battery system and a second battery system in parallel configuration, and a pulse width modulation device and (b) being interconnectable to a load. Each of the first and second battery systems has, in series and in order, a first voltage sensor, a resistor, a second voltage sensor, a string of battery cells, and a switching device. The first and second voltage sensor, in each battery system, measures an electrical current, used to calculate the voltage drop across each resistor. The voltage drop values for each battery system determine whether the pulse width modulation device alters or maintains the pulse width modulation applied to each battery system's switching device. By maintaining or altering the pulse width modulation applied to each switching device, the apparatus effectively balances the electrical current discharge from each battery system. ## Claims ### Claim 1 An apparatus to balance a discharge in parallel battery configuration comprising: a battery pack (a) having a first battery system and a second battery system in parallel configuration, a pulse width modulation device, and a computer processing unit, and (b) being interconnectable to a load; wherein the first battery system and the second battery system each has, in series and in order, a first voltage sensor, a resistor, a second voltage sensor, a string of battery cells that generates a current, and a switching device; the first voltage sensor, in each battery system, measures an electrical current's voltage prior to the electrical current passing through the resistor, and the second voltage sensor, measures the electrical current's voltage after the electrical current passes through the resistor; the first and second voltage measurements from the first and second voltage sensors in each battery system are transmitted to the computer processing unit; the computer processing unit calculates the voltage drop for each battery system; and based on the voltage drop calculations, the computer processing unit transmits a signal to the pulse width modulation device to transmit a distinct signal to each switching device in each battery system that alters or maintains the pulse width modulation applied to each switching device in each battery system, to thereby effectively balance the electrical current discharge from each battery system. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein at least one of the string of battery cells has at least two individual battery cells in series configuration. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the electrical current is transmitted to the load only when the switching device is closed and the battery pack is connected to the load. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the pulse width modulation device and the computer processing unit are a single device. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein at least one of the string of battery cells has a discharge battery cell and a receiving battery cell in series configuration. ### Claim 6 (depends on 5) The apparatus of claim 5 wherein positioned between the discharge battery cell and the receiving battery cell is at least one battery cell in series with the discharge battery cell and the receiving battery cell. ### Claim 7 (depends on 5) The apparatus of claim 5 wherein positioned between the discharge battery cell and the receiving battery cell is at least two battery cells in parallel with the discharge battery cell and the receiving battery cell. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein the switching device is a field effect transistor. ### Claim 9 (depends on 1) The apparatus of claim 1 wherein the resistor is 5 ohms or less, but greater than zero. ### Claim 10 (depends on 1) The apparatus of claim 1 wherein the distinct signal to each switching device in each battery system that alters or maintains the pulse width modulation applied to each switching device in each battery system can result in the following signals selected from the group consisting of (a) maintaining the pulse width modulation applied to each switching device; (b) altering the pulse width modulation applied to each switching device; (c) maintaining the pulse width modulation applied to the switching device in the first battery system and altering the pulse width modulation applied to the switching device in the second battery system; and (d) maintaining the pulse width modulation applied to the switching device in the second battery system and altering the pulse width modulation applied to the switching device in the first battery system. ### Claim 11 An apparatus, not connected to any other battery source, to balance a discharge in parallel battery configuration comprising: a battery pack (a) having a first battery system and a second battery system in parallel configuration, a pulse width modulation device, and a computer processing unit, and (b) being interconnectable to a load; the first battery system and the second battery system each has, in series and in order, a first voltage sensor, a resistor, a second voltage sensor, a string of battery cells that generates a current, and a switching device; the first voltage sensor, in each battery system, measures an electrical current's voltage prior to the electrical current passing through the resistor, and the second voltage sensor, in each battery system, measures the electrical current's voltage after the electrical current passes through the resistor; the first and second voltage measurements from the first and second voltage sensors in each battery system are transmitted to the computer processing unit; the computer processing unit calculates the voltage drop for each battery system; based on the voltage drop calculations, the computer processing unit transmits a signal to the pulse width modulation device to transmit a distinct signal to each switching device in each battery system that alters or maintains the pulse width modulation applied to each switching device in each battery system, to thereby effectively balance the electrical current discharge from each battery system; and is not connected to any other battery source. ### Claim 12 (depends on 11) The apparatus of claim 11 wherein at least one of the string of battery cells has at least two individual battery cells in series configuration. ### Claim 13 (depends on 11) The apparatus of claim 11 wherein the electrical current is transmitted to the load only when the switching device is closed and the battery pack is connected to the load. ### Claim 14 (depends on 11) The apparatus of claim 11 wherein the pulse width modulation device and the computer processing unit are a single device. ### Claim 15 (depends on 11) The apparatus of claim 11 wherein at least one of the string of battery cells has a discharge battery cell and a receiving battery cell in series configuration. ### Claim 16 (depends on 15) The apparatus of claim 15 wherein positioned between the discharge battery cell and the receiving battery cell is at least one battery cell in series with the discharge battery cell and the receiving battery cell. ### Claim 17 (depends on 15) The apparatus of claim 15 wherein positioned between the discharge battery cell and the receiving battery cell is at least two battery cells in parallel with the discharge battery cell and the receiving battery cell. ### Claim 18 (depends on 11) The apparatus of claim 11 wherein the distinct signal to each switching device in each battery system that alters or maintains the pulse width modulation applied to each switching device in each battery system can result in the following signals selected from the group consisting of (a) maintaining the pulse width modulation applied to each switching device; (b) altering the pulse width modulation applied to each switching device; (c) maintaining the pulse width modulation applied to the switching device in the first battery system and altering the pulse width modulation applied to the switching device in the second battery system; and (d) maintaining the pulse width modulation applied to the switching device in the second battery system and altering the pulse width modulation applied to the switching device in the first battery system. ### Claim 19 The method of using an apparatus, not connected to any other battery source, to balance a discharge in parallel battery configuration, the apparatus having: a battery pack (a) having a first battery system and a second battery system in parallel configuration, a pulse width modulation device, and a computer processing unit and (b) being interconnectable to a load; the first battery system and the second battery system each has, in series and in order, a first voltage sensor, a resistor, a second voltage sensor, a string of battery cells that generates a current, and a switching device; measuring through the first voltage sensor, in each battery system, an electrical current's voltage prior to the electrical current passing through the resistor; measuring through the second voltage sensor, in each battery system, the electrical current's voltage after the electrical current passes through the resistor; calculating the voltage drop for each battery system through the first and second voltage measurements from the first and second voltage sensors in each battery system; altering or maintaining, based on the voltage drop calculation for each battery system, the pulse width modulation applied to each individual switching device in each battery system to effectively balance the electrical current discharge from every battery system. ### Claim 20 (depends on 19) The method of claim 19 wherein the distinct signal to each switching device in each battery system that alters or maintains the pulse width modulation applied to each switching device in each battery system can result in the following signals selected from the group consisting of (a) maintaining the pulse width modulation applied to each switching device; (b) altering the pulse width modulation applied to each switching device; (c) maintaining the pulse width modulation applied to the switching device in the first battery system and altering the pulse width modulation applied to the switching device in the second battery system; and (d) maintaining the pulse width modulation applied to the switching device in the second battery system and altering the pulse width modulation applied to the switching device in the first battery system.