Valid Charge Termination
48
SLUUBD3D – September 2015 – Revised September 2018
Copyright © 2015–2018, Texas Instruments Incorporated
Charge Algorithm
FET Options[PCHG_EN]
FET Used
0
PCHG
1
CHG
Class
Subclass
Name
Type
Min
Max
Default
Unit
Charge Algorithm
Fast Charging
Voltage
I2
0
5000
4200
mV
Charge Algorithm
Fast Charging
Current
I2
0
32767
3000
mA
Charge Algorithm
Pre-Charging
Current
I2
0
32767
100
mA
Charge Algorithm
Pre-Charging
Start Voltage
I2
0
32767
2500
mV
Charge Algorithm
Pre-Charging
Recovery Voltage
I2
0
32767
2900
mV
5.3
Valid Charge Termination
The charge termination condition must be met to enable valid charge termination. The device has the
following actions at charge termination, based on the flags settings:
•
If
FETOption[CHGFET] = 1
, CHG FET turns off.
•
If
CEDV Gauging Configuration[CSYNC]
= 1,
RemainingCapacity()
=
FullChargeCapacity()
.
•
If
SBS Gauging Configuration[RSOCL]
= 1,
RelativeStateOfCharge()
and
RemainingCapacity()
are
held at 99% until charge termination occurs. Only on entering charge termination is 100% displayed.
•
If
SBS Gauging Configuration[RSOCL]
= 0,
RelativeStateOfCharge()
and
RemainingCapacity()
are
not held at 99% until charge termination occurs. Fractions of % greater than 99% are rounded up to
display 100%.
Status
Condition
Action
Charging
GaugingStatus()[REST]
= 0 AND
GaugingStatus()[DSG]
= 0
Charge Algorithm active
Valid Charge
Termination
All of the following conditions must occur for two
consecutive 40-s periods:
Charging (that is,
BatteryStatus[DSG]
= 0) AND
AverageCurrent()
<
Charge Term Taper
Current
AND
Max (
CellVoltage1..15()
) +
Charge Term
Voltage
≥
ChargingVoltage()
/number of cells in
series AND
The accumulated change in capacity > 0.25
mAh since current and voltage termination
conditions where first detected.
ChargingStatus()[VCT]
= 1
ChargingVoltage()
= Charging Algorithm
ChargingCurrent()
= Charging Algorithm
BatteryStatus()[FC]
= 1 and
GaugingStatus()[FC]
= 1 if
SOCFlagConfig A[FCSETVCT]
= 1
BatteryStatus()[TCA]
= 1 and
GaugingStatus()[TCA]
= 1 if
SOCFlagConfig B[TCASETVCT]
= 1
Class
Subclass
Name
Type
Min
Max
Default
Unit
Charging Algorithms
Termination Config
Charge Term Taper
Current
I2
0
32767
250
mA
Charging Algorithms
Termination Config
Charge Term Voltage
I2
0
32767
75
mV
5.4
Charge and Discharge Alarms
The
[TCA]
and
[FC]
bits in
BatteryStatus()
can be set at charge termination as well as based on RSOC
when the device is in CHARGE state (that is,
BatteryStatus[DSG]
= 0). If more than one set and clear
conditions are selected, then the corresponding flag will be set whenever a valid set or clear condition is
met. The same functionality is applied to the
[TDA]
and
[FD]
bits in
BatteryStatus()
.
Per the
Smart Battery Data Specification v1.1
, TDA is only active while discharging and TCA is only active
while charging but the bq78350-R1 will only follow this particular requirement if
SOC Flag Config
[SBS_COMP]
= 1. By default, the TCA and TDA flags will not change based on current magnitude or
direction.
