SLUUCD5 January 2023 BQ27427
Subclass | Subclass ID | Offset | Type | Name | Value | Unit | ||
---|---|---|---|---|---|---|---|---|
Min | Max | Default | ||||||
State | 82 | 5 | H1 | Load Select/Mode | 0 | FF | 81 | 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. This provides a better estimation of remaining run time, especially close to the end of discharge where current increases to compensate for decreasing battery voltage. 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.
Load Select defines the type of power or current model to be used to compute load-compensated capacity in the Impedance Track algorithm. By default, Load Select is set to 1, which means the IT algorithm will use a running average of the current discharge period. Once the discharge stops, the algorithm stores the average in data flash as the Avg I Last Run and Avg P Last Run variables. For simulations during RELAXATION, CHARGE, and at the start of DISCHARGE (since a new average has not been gathered), it would use data flash values for simulations. Once the discharge has lasted 500 seconds, the gauge re-simulates using the new running average. Thereafter, during discharge, it uses the continuous running average for any subsequent simulations.
Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 | |
---|---|---|---|---|---|---|---|---|
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 #GUID-6CCB31AD-6297-4147-89BE-44BC0267712A/SLUUA86-1979 and #GUID-6CCB31AD-6297-4147-89BE-44BC0267712A/SLUUA86-19791 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 #GUID-6CCB31AD-6297-4147-89BE-44BC0267712A/SLUUA86-1979 and #GUID-6CCB31AD-6297-4147-89BE-44BC0267712A/SLUUA86-19791 for operational details. Default is 1. |
If Load Mode = 0 (Constant current), then the following options are available:
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:
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 . |
5 | Reserved |
6 | User_Rate-mW: Use the value in User Rate-mW. This provides a user-configurable load model. |
All others | Reserved |