bq27441 Data Memory Parameter Descriptions
6.4.2.3.4 Load Select, Load Mode
Subclass
Subclass
Offset
Type
Name
Value
Unit
ID
Min
Max
Default
State
82
5
H1
Load Select/Mode
0x00
0xFF
0x81
Hex
Load Mode
configures the fuel gauge to use either a constant-current or constant-power model for the
Impedance Track™ algorithm. When
Load Mode
is 0, the Constant Current Model is used. When
Load
Mode
is 1 (default), the Constant Power Model is used. The
CONTROL_STATUS [LDMD]
bit reflects the
status of
Load Mode
.
Load Select
is used in conjunction with
Load Mode
to define the type of load model that computes the
load-compensated capacity in the Impedance Track™ algorithm.
If
Load Mode
= 0 (Constant current), then the following options are available:
Table 6-9. Load Select/Mode Parameter Encoding
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
Load Mode
RSVD
RSVD
RSVD
RSVD
Load Select[2:0]
Default =
1
0
0
0
0
0
0
1
0x81
Load Mode = Bit 7 contains the value for
Load Mode
. Refer to
and
for operational details.
RSVD = Reserved. Set to 0 for proper operation.
Load Select[2:0] = Bits 2:0 contain the value for
Load Select
. Refer to
and
for operational details.
Default is 1.
Table 6-10. Current Model Used When Load Mode = 0
Load Select Value
Current Model Used
0
Average discharge current from previous cycle: There is an internal register (
Avg I Last Run
) that records
the average discharge current through each entire discharge cycle. The previous average is stored in this
register.
1 (default)
Present average discharge current: This is the average discharge current from the beginning of this
discharge cycle until present time.
2
Average current: based off the
AverageCurrent()
3
Current: based off of a low-pass-filtered version of
AverageCurrent()
(
τ
= 14 s)
4
Design capacity / 5: C Rate based off of
Design Capacity
/ 5 or a C / 5 rate in mA.
5
Reserved
6
User_Rate-mA: Use the value in
User Rate-mA
. This provides a user-configurable load model.
All others
Reserved
If
Load Mode
= 1 (Constant power) then the following options are available:
Table 6-11. Power Model Used When Load Mode = 1
Load Select Value
Power Model Used
0
Average discharge power from previous cycle: There is an internal register (
Avg P Last Run
) that records
the average discharge power through each entire discharge cycle. The previous average is stored in this
register.
1 (default)
Present average discharge power: This is the average discharge power from the beginning of this discharge
cycle until present time.
2
Average current × voltage: based off the
AverageCurrent()
and
Voltage()
.
3
Current × voltage: based off of a low-pass-filtered version of
AverageCurrent()
(
τ
= 14 s) and
Voltage()
4
Design energy / 5: C Rate based off of
Design Energy
/5 or a C / 5 rate in mA .
43
SLUUAC9A – December 2013 – Revised May 2015
Data Memory
Copyright © 2013–2015, Texas Instruments Incorporated