HI EVERYONE!!
after selecting the suitable ChemID and generating an aux-file with our battery setup, we still have issues with the SOC readings.
FIRST: When starting to discharge a fully charged battery (charge termination was controlled by "Charge Completion Pack Voltage Qualifier" and "Charge Completion Taper Current Qualifier"; minimum measured cell voltage @ EndOfCharge was 3,65Vpc ) we see a jump downwards in rel.SOC reading: SOC reads 100% during the whole rest period, but after starting discharging the SOC-value drops suddenly:
The longer the rest period since the full charge cycle, the bigger the drop of the rel.SOC. Starting discharge immediately after charge has been terminated, the deviation was almost zero. Waiting with discharge for two days, the initial SOC drop after starting discharge was -6% followed by another jump of -5% 8 minutes later. See "discharge after 2days rest.pdf"/cfs-file/__key/communityserver-discussions-components-files/196/8420.discharge-after-2days-rest.pdf
In case the rest period is 6 full days, the initial drop was -33%(!) even the battery was still fully charged at the begin of discharging
We think, that this might come from the continousely falling OCV of the LiFePO4 battery during rest after charge was terminated. This voltage is constantly falling over a period of days. Starting at the level of fully charged (in our case 3,68Vpc) dropping to 3,349Vpc after 6 days without any kind of load connected. Does have anyone an idea how to solve this?
Our configuration file: Knapp_20170202.dat
SECOND: We did a following measurment (log file): 2017.3.1-13.12.13_BattLog.xlsx . We have charged the battery until CC Flag has turned on, then without waiting for OCV Idle Qualifier Time, we fully discharged the battery (until DC Flag turned on) and repeated this process multiple times. We observed that after every cycle the SOC decreased for ~1%. Does anyone has an idea what could possibly influence such a behavior?
We would really appreciate your help!
Thanks in advance!
Vladimir B.
Vladimir B.
