bq27441 Data Memory Parameter Descriptions
The gauging algorithm transitions between three states: discharge, charge, and relaxation modes of
operation. During charge mode, the
[DSG]
bit of the
Flags()
register is cleared, and during discharge and
relaxation mode it is set. Entry and exit for each mode is controlled by six parameters in the Current
Thresholds Subclass.
The discharge current threshold can be calculated as
Design Capacity
/ (
Dsg Current Threshold
× 0.1).
The default is effectively C / 16.7.
The charge current threshold can be calculated as
Design Capacity
/ (
Chg Current Threshold
× 0.1).
The default is effectively C / 10.
The quit current threshold can be calculated as
Design Capacity
/ (
Quit Current
× 0.1). The default is
effectively C / 25.
Charge mode is exited and relaxation mode is entered when
EffectiveCurrent()
goes below the quit
current threshold for the number of seconds specified in
Charge Relax Time
(default 60 s). Discharge
mode is entered when
EffectiveCurrent()
goes below the discharge current threshold for
Quit Relax Time
(default 1 s). Discharge mode is exited and relaxation mode is entered when
EffectiveCurrent()
goes
above negative quit current threshold for
Dsg Relax Time
(default 60 s). Charge mode is entered when
EffectiveCurrent()
goes above the charge current threshold for
Charge Relax Time
(default 60 s).
Figure 6-1. Example of Algorithm Operation Mode Changes With Varying DataRAM.Average Current()
6.4.2.2.2 Max IR Correct
Subclass
Subclass
Offset
Type
Name
Value
Unit
ID
Min
Max
Default
Current
81
12
U2
Max IR Correct
0
1000
400
mV
Thresholds
The
Max IR Correct
is a maximum IR correction applied to OCV lookup under load. It only applies to OCV
lookup after wakeup with detected charge current when the gauge needs to establish capacity baseline,
but the current is already flowing.
41
SLUUAC9A – December 2013 – Revised May 2015
Data Memory
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