US 11,747,403 B2
Method for ascertaining the state of charge of an electrical energy storage unit
Christel Sarfert, Korntal-Muenchingen (DE); Ganesh Susmitha, Stuttgart (DE); and Shashank Holavanahalli, Stuttgart (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Feb. 4, 2021, as Appl. No. 17/167,164.
Claims priority of application No. 10 2020 201 506.6 (DE), filed on Feb. 7, 2020.
Prior Publication US 2021/0247454 A1, Aug. 12, 2021
Int. Cl. G01R 31/388 (2019.01); H02J 7/00 (2006.01)
CPC G01R 31/388 (2019.01) [H02J 7/0048 (2020.01)] 7 Claims
OG exemplary drawing
 
1. A method for ascertaining the state of charge of an electrical energy storage unit (41), the method comprising the steps of:
a) ascertaining a voltage gradient at least based on a detected first voltage value of the electrical energy storage unit;
b) comparing the ascertained voltage gradient with a predefined voltage gradient threshold value;
c) ascertaining a period of time in which the electrical energy storage unit (41) is in disuse based on an absolute value of a drawn and/or output a current falling below a no-load current threshold value in terms of absolute value; and
d) ascertaining the state of charge of the electrical energy storage unit (41) based on the comparison and the period of time.