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bq27500
bq27501
System-Side Impedance Track™ Fuel Gauge
SLUS785 – SEPTEMBER 2007
4.1.1.16 MaxLoadCurrent( ): 0x1e/0x1f
This read-only function returns a signed integer value, in units of mA, of the maximum load conditions.The MaxLoadCurrent( ) is an adaptive measurement which is initially reported as the maximum loadcurrent programmed in Initial Max Load Current. If the measured current is ever greater than Initial MaxLoad Current, then MaxLoadCurrent( ) updates to the new current. MaxLoadCurrent( ) is reduced to theaverage of the previous value and Initial Max Load Current whenever the battery is charged to full aftera previous discharge to an SOC less than 50%. This prevents the reported value from maintaining anunusually high value.
4.1.1.17 MaxLoadTimeToEmpty( ): 0x20/0x21
This read-only function returns an unsigned integer value of the predicted remaining battery life at themaximum load current discharge rate, in minutes. A value of 65535 indicates that the battery is not beingdischarged.
4.1.1.18 AvailableEnergy( ): 0x22/0x23
This read-only function returns an unsigned integer value of the predicted charge or energy remaining inthe battery. The value is reported in units of mWh.
4.1.1.19 AveragePower( ): 0x24/0x25
This read-word function returns an unsigned integer value of the average power of the current discharge.A value of 0 indicates that the battery is not being discharged. The value is reported in units of mW.
4.1.1.20 TimeToEmptyAtConstantPower( ): 0x26/0x27
This read-only function returns an unsigned integer value of the predicted remaining operating time if thebattery is discharged at the AveragePower( ) value in minutes. A value of 65535 indicatesAveragePower( ) = 0. The fuel gauge automatically updates TimeToEmptyatContantPower( ) based on theAveragePower( ) value every 1s.
4.1.1.21 CycleCount( ): 0x2a/0x2b
This read-only function returns an unsigned integer value of the number of cycles the battery hasexperienced with a range of 0 to 65535. One cycle occurs when accumulated discharge ≥CC Threshold.
4.1.1.22 StateOfCharge( ): 0x2c/0x2d
This read-only function returns an unsigned integer value of the predicted remaining battery capacityexpressed as a percentage of FullChargeCapacity( ), with a range of 0 to 100%.
Extended commands offer additional functionality beyond the standard set of commands. They are used inthe same manner; however unlike standard commands, extended commands are not limited to 2-bytewords. The number of commands bytes for a given extended command ranges in size from single tomultiple bytes, as specified in Table 4-5 . For details on the SEALED and UNSEALED states, seeSection 4.4 Access Modes.
Table 4-5. Extended Data Commands
COMMAND SEALED UNSEALEDNAME UNITSCODE ACCESS
(1) (2)
ACCESS
(1) (2)
Reserved RSVD 0x34...0x3b N/A R R
DesignCapacity( ) DCAP 0x3c / 0x3d mAh R R
DataFlashClass( )
(2)
DFCLS 0x3e N/A N/A R/W
DataFlashBlock( )
(2)
DFBLK 0x3f N/A R/W R/W
Authenticate( )/BlockData( ) A/DF 0x40 …0x53 N/A R/W R/W
AuthenticateCheckSum( )/BlockData( ) ACKS/DFD 0x54 N/A R/W R/W
(1) SEALED and UNSEALED states are entered via commands to CNTL 0x00/0x01.(2) In sealed mode, data flash CANNOT be accessed through commands 0x3e and 0x3f.
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