Battery cell management

• Main Authors: Andrew Robert Williams, Paul Spendley, Ian Michael Harrop, James Andrew Thompson, Nicolas Philip Webb
• Format: Patent
• Language: English
• Published: 22.02.2017
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC EQUIPMENT OR PROPULSION OF ELECTRICALLY-PROPELLEDVEHICLES; ELECTRICITY; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES, IN GENERAL; GENERATION; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PERFORMING OPERATIONS; PHYSICS; SYSTEMS FOR STORING ELECTRIC ENERGY; TESTING; TRANSPORTING; VEHICLES IN GENERAL

A battery system, suitable for use in electric vehicles or stationary power applications, comprises a plurality of series connected cells 101a-c forming a battery string 105 connected in series with a power line, and a plurality of cell monitoring units 102a-c connected in parallel with one or more of the series connected cells. A battery management unit 104 is connected to opposite ends of the battery string and communicates over the power line 103 with the cell monitoring units, each of which may transmit cell condition information. Each series connected cell may be connected in parallel with further cells, and each cell monitoring unit may transmit information including cell voltage, temperature, charge or discharge state and impedance. In an alternate battery system, each cell monitoring unit comprises a first control module (301a-c, figure 3) to monitor a cell voltage, and a second control module (302a-c, figure 3) to disconnect the first control module if the cell voltage falls below a predetermined level.