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BQ4050: BQ4050

Part Number: BQ4050
Other Parts Discussed in Thread: GPCCEDV,

Hi

The customer design with BQ4050, they use fix EDV mode. the GPCCEDV report as below.

GPC CEDV tool, rev=60
Configuration used in present fit
ProcessingType=1
NumCellSeries=4
CellTermV=2600
LearnSOC%=5
FitMaxSOC%=8
FitMinSOC%=3
ChemType=4
ElapsedTimeColumn=0
VoltageColumn=1
TemperatureColumn=2
CurrentColumn=3

CEDV parameters resulting from the fit. If EDVV bit is set to 1, EMF and EDVR0 have to be multiplied by the number of serial cells when written to data flash

EMF 3658
EDVC0 670
EDVC1 0
EDVR1 1
EDVR0 3205
EDVT0 4797
EDVTC 11
VOC75 13271
VOC50 13164
VOC25 12962


Recommended SOC deviation tolerance at EDV2 point is < 5% for low temperature and <3% for room and high temperature

Deviations for this set of parameters are given below for each file

file SOC error, % pass
roomtemp_lowrate.csv -1.90898547666049 1
roomtemp_highrate.csv -5.13123879175504 0
hightemp_lowrate.csv -1.90898547666049 1
hightemp_highrate.csv -1.85393898011949 1
lowtemp_lowrate.csv -6.17498811567494 0
lowtemp_highrate.csv -14.4965595720401 0

Accuracy Error: Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule

Project 1: Lithium iron phosphate battery, 4S10P, 40AH, after fully charged, discharge from 100% to 75%, stand at low temperature -10°C for 4-6H, check SOC=77%

Project 2: Lithium iron phosphate battery, 4S5P, 23AH, charged to 100% at a low temperature of 2-4°C, turned to room temperature for 1.5 days, no change in SOC, and placed at 35°C for about 2 hours, SOC changed to 83%

Project 3: ternary lithium battery, 4S16P, 41.4AH, temperature cycle, stand at -20°C for 5H, turn to high temperature at 75°C for 5H, after the end, place at room temperature for 8H, SOC100%->46% and then check after 12H , SOC=36%

All of the above test at low temperature. Under this working condition, the cell voltage has almost no change, but is the SOC jump. 

What is the reason for SOC jump?

Waiting for your reply.

Thanks

Star

  • Hello Star, 

    If the customer uses fixed EDV mode, they should not be using the GPCCEDV tool. This tool is for when the Compensated EDV feature is used.

    For simplicity, it is best to input manually the Voltage % DOD in the CEDV Profile. This can be obtained from the GPCCEDV report.

    Please provide the following:
    1- GPCCEDV report
    2- the matched ChemID using the GPCCHEM tool. 
    3- configuration gg file.
    4- A log data that shows a fully discharge cycle from a full cell.
    5- Terminate Voltage of application
    6- Fully charge voltage of application

    Regards,
    Jose Couso