BQ2063_15 Datasheet, PDF (46/60 Pages) Texas Instruments – SBS v1.1-COMPLIANT Li-ION GAS-GAUGE IC

bq2063
Not Recommended For New Designs
SBS v1.1ĆCOMPLIANT LiĆION GASĆGAUGE IC
WITH PROTECTOR INTERFACE
SLUS468E− MAY 2001 − REVISED APRIL 2002
PROGRAMMING INFORMATION
EVD discharge rate and temperature compensation (continued)
Typical values for the EDV compensation factors, based on overall pack voltages for a Li-lon 3s3p 18650 pack,
are
EMF = 11550
T0 = 4475
C0 = 235
C1 = 0
R0 = 5350
R1 = 250
TC = 3
The graphs in Figures 11 and 12 show the calculated EDV0, EDV1, and EDV2 thresholds versus capacity using
the typical compensation values for different temperatures and loads for a Li-Ion 3s3p 18650 pack. The
compensation values vary widely for different cell types and manufacturers and must be matched exactly to the
unique characteristics for optimal performance.
11.5
11.0
EDV2
10.5
EDV1
10.0
VOLTAGE
vs
CAPACITY
Battery Low % = 7%
Load = 500 mA
20°C
45°C
9.5
9.0
8.5
11.5
11.0
EDV2
10.5
EDV1
10.0
9.5
VOLTAGE
vs
CAPACITY
Battery Low % = 7%
TA = 35°C
500 mA
1A
2A
9.0
8.5
8.0
8.0
7.5
0 1 2 3 4 5 6 7 8 9 10
Capacity − %
7.5
EDV0
7.0
0 1 2 3 4 5 6 7 8 9 10
Capacity − %
Figure 11. EDV Calculations vs Capacity for
Various Temperatures
Figure 12. EDV Calculations vs Capacity for
Various Loads
overload current threshold
The Overload Current threshold is a 16-bit value stored in EE 0x46-0x47 in mA units.
midrange capacity corrections
Three voltage-based thresholds, VOC25 EE 0x6c-0x6d, VOC50 EE 0x6e-0x6f, and VOC75 EE 0x70-0x71, are
used to test the accuracy of the RM based on open-circuit pack voltages. These thresholds are stored in the
EEPROM in 2s complement of voltage in mV. The values represent the open-circuit battery voltage at which
the battery capacity should correspond to the associated state of charge for each threshold.
46
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265