Relaxation time constants give valuable information about a lithium polymer battery cell's state-of-charge. Moreover, determination of these time constants can be performed in real time by fitting exponential functions to transient voltage or current patterns.
STATEMENT OF GOVERNMENT SUPPORT
 The invention described and claimed herein was made in part utilizing funds supplied by the U.S. Department of Energy under Contract No. DE-EE0005449. The Government has certain rights in this invention.