Capacitance Sensor in a Battery

1 . A battery assembly, comprising:

an electrochemical structure;

a pouch disposed around the electrochemical structure;

a first electrode incorporated into the battery assembly;

a second electrode incorporated into the battery assembly; and

a controller in communication with the first and second electrode programmed to measure a capacitance between the first electrode and second electrode.

2 . The battery assembly of claim 1 , wherein the second electrode is incorporated into the pouch.

3 . The battery assembly of claim 1 , wherein the second electrode is movable with the pouch.

4 . The battery assembly of claim 1 , wherein the first electrode is affixed to the electrochemical structure.

5 . The battery assembly of claim 1 , wherein the first electrode is incorporated into the pouch.

6 . The battery assembly of claim 1 , wherein the first electrode is a sense electrode disposed within the pouch and the second electrode is a transmit electrode incorporated into the pouch.

7 . The battery assembly of claim 1 , wherein the controller is programmed to send an alert when a capacitance between the first electrode and the second electrode reaches a predetermined value.

8 . The battery assembly of claim 1 , further comprising a floating coupler movable with the pouch.

9 . The battery assembly of claim 8 , wherein at least one of the first electrode and second electrode is fixed to a reference surface within the pouch and a distance between the floating coupler and at least one of the first electrode and the second electrode affects a capacitance between the first electrode and the second electrode.

10 . The battery assembly of claim 9 , wherein the reference surface is part of the electrochemical structure.

11 . A computer-program product associated with a battery assembly, the computer-program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to:

determine a capacitance between a first electrode incorporated into the battery assembly and a second electrode incorporated into the battery assembly.

12 . The computer-program product of claim 11 , wherein the instructions are executable by a processor to:

send an alert when capacitance between the first electrode and the second electrode reaches a predetermined value threshold.

13 . The computer-program product of claim 11 , wherein at least one of the first electrode and the second electrode is incorporated into the pouch.

14 . The computer-program product of claim 11 , further comprising a floating coupler disposed within the battery assembly and movable with the pouch;

wherein a distance between the at least one of the first electrode and the second electrode affects a capacitance between the first electrode and the second electrode.

15 . A battery assembly, comprising:

a pouch;

a capacitance sensor located at least in part in the pouch; and

a controller that is programmed to determine a swell size of the pouch based at least in part on the capacitance measurement of the capacitance sensor.

16 . The battery assembly of claim 15 , wherein the capacitance sensor includes at least one electrode that is movable with a portion of the pouch.

17 . The battery assembly of claim 15 , wherein the capacitance measurement is affected by a floating coupler that is movable with at least a portion of the pouch.

18 . The battery assembly of claim 15 , wherein a sense electrode of the capacitance sensor is disposed within the pouch and a transmit electrode of the capacitance sensor is incorporated into the pouch.

19 . The battery assembly of claim 18 , wherein the capacitance sensor is a mutual capacitance sensor with a separate drive and sense electrode.

20 . The battery assembly of claim 15 , wherein the capacitance sensor is a self-capacitance sensor with an electrode configured to both drive a voltage and sense the capacitance measurement.