Patent ID: 9128159
Filing Date: 2015-09-08
Classification: G01R,G06F,H02J

Abstract:
1. A method for estimating a charge capacity of a lithium iron-phosphate battery pack using data from a plug-in charge event, said method comprising: initiating the plug-in charge event of the battery pack, recording terminal voltage data during the charge event using a voltmeter, and recording charging current data during the charge event using a current sensor; completing the plug-in charge event and storing the terminal voltage data and the charging current data; determining open circuit voltage values from the terminal voltage data at two points in time from the plug-in charge event, including, for at least one of the two points in time, calculating the open circuit voltage by taking the terminal voltage at the point in time and subtracting the charging current at the point in time multiplied by a predetermined battery pack resistance; determining state of charge values from the open circuit voltage values at the two points in time from the plug-in charge event; calculating, using a controller including a processor, the charge capacity of the battery pack using the state of charge values and the charging current data; and communicating the charge capacity of the battery pack, by the controller, to a user of the battery pack.