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SLUUBD3D–September 2015–Revised September 2018
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CEDV Gas Gauging
9.1.7 End-of-Discharge Thresholds and Capacity Correction
The bq78350-R1 monitors the battery for three low-voltage thresholds, EDV0, EDV1, and EDV2. The
bq78350-R1 uses the lowest, single-cell value from individual cell voltage measurements for EDV
threshold comparison when CEDV Gauging Configuration [EDV_EXT_CELL] = 0. However, if this bit =
1, then the ExternalCellVoltage() is used.
With either Compensated or Fixed EDV configurations, the configured voltage to be used must be equal to
or below the appropriate voltage for the corresponding EDV2,1,0 Hold Time to ensure correct detection
under all load types. EDV1 Detection and its associated hold time do not begin until EDV2 has been
detected and the EDV2 flag is set. Similarly, EDV0 detection does not begin before the EDV1 flag is set.
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg Fixed EDV0 Integer 2 0 32767 3031 mV
Fuel
Gauging
CEDV Cfg Fixed EDV1 Integer 2 0 32767 3385 mV
Fuel
Gauging
CEDV Cfg Fixed EDV2 Integer 2 0 32767 3501 mV
Fuel
Gauging
CEDV Cfg
EDV0 Hold
Time
Unsigned
Integer
1 1 255 1 s
Fuel
Gauging
CEDV Cfg
EDV1 Hold
Time
Unsigned
Integer
1 1 255 1 s
Fuel
Gauging
CEDV Cfg
EDV2 Hold
Time
Unsigned
Integer
1 1 255 1 s
If the [EDV_CMP] bit in CEDV Gauging Configuration is set, automatic EDV compensation is enabled
and the bq78350-R1 computes the EDV0, EDV1, and EDV2 thresholds based on values stored in CEDV
Cfg subclass of data flash and the battery's current discharge rate and temperature. However, if
[FIXED_EDV0] bit in CEDV Gauging Configuration is set, then even if [EDV_CMP] = 1, then EDV0 is a
fixed voltage value and is not compensated.
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg EMF
Unsigned
Integer
2 0 65535 3743 mV
Fuel
Gauging
CEDV Cfg
EDV C0
Factor
Unsigned
Integer
2 0 65535 149 —
Fuel
Gauging
CEDV Cfg
EDV R0
Factor
Unsigned
Integer
2 0 65535 867 —
Fuel
Gauging
CEDV Cfg
EDV T0
Rate Factor
Unsigned
Integer
2 0 65535 4030 —
Fuel
Gauging
CEDV Cfg
EDV R1
Rate Factor
Unsigned
Integer
2 0 65535 316 —
Fuel
Gauging
CEDV Cfg
EDV TC
Factor
Unsigned
Integer
1 0 255 9 —
Fuel
Gauging
CEDV Cfg
EDV a0 Age
Factor
Unsigned
Integer
1 0 255 0
The bq78350-R1 disables EDV detection if the measured battery discharge current magnitude (–Current())
meets or exceeds the Overload Current threshold, which is scaled by IPSCALE. The bq78350-R1
resumes EDV threshold detection after C drops below the Overload Current threshold. Any EDV
threshold detected is reset after charge is applied and [VDQ] is then cleared after RC has increased by a
value of 10, which is scaled by IPSCALE.
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg
Overload
Current
Integer 2 0 32767 5000 mA
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