This device supports
five
modes, but the current consumption varies, based on firmware control of certain
functions and modes of operation:
- NORMAL mode: In this mode, the device performs
measurements, calculations, protections, and data updates every 250-ms
intervals. Between these intervals, the device
operates
in a reduced power
state
to minimize total average current consumption. Battery protections are
continuously
monitored and both protection NFETs are typically on.
- SLEEP mode: In this mode, the device performs
measurements, calculations, and data updates in adjustable time intervals.
Between these intervals, the device
operates
in a reduced power stage to minimize total average current consumption. Battery
protections are
continuously
monitored and both protection NFETs are typically on.
- SHIP mode:
In
this mode, the device measures voltage and temperature very infrequently and at
shorter ADC conversion times, and current is not measured or coulomb counted.
Current is assumed to
be,
and reported
as,
0 mA. Therefore, the device tracks the battery's state-of-charge from OCVs. The
measurements performed each interval are
cell
voltage,
temperature,
and PACK
voltage
(every fourth interval). Processing is minimized by reducing the number of
calculations. Some calculations are performed less frequently: only after
voltage and temperature are measured. These less frequent calculations include
updating firmware-based protections, lifetime data, and the voltage and
temperature
ranges
of the advanced charge algorithm. Other calculations, such as updating
RemainingCapacity() and
FullChargeCapacity(),
are not performed at all with the assumption the system is off and will not
communicate with the gauge. Battery protections are
continuously
monitored and both protection NFETs remain on, typically.
- SHELF mode:
In
this mode,
power
consumption is reduced even further from SHIP mode by turning off the CHG and
DSG NFETs and all hardware-based protections. Due to this, no external power is
available to the system in SHELF
mode.
The device measures voltage and temperature very infrequently
and at shorter ADC conversion times, and current is not measured or coulomb
counted. Current is assumed to
be,
and reported
as,
0 mA. Therefore, the device tracks the battery's state-of-charge from voltage
measurements. The measurements performed each interval are
cell
voltage,
temperature
and PACK
voltage
(every fourth interval). Processing is minimized by reducing the number of
calculations. Some calculations are performed less frequently: only after
voltage and temperature are measured. These less frequent calculations include
updating firmware-based protections, lifetime data, and the voltage and
temperature
ranges
of the advanced charge algorithm. Other calculations, such as updating
RemainingCapacity() and
FullChargeCapacity(),
are not performed at all with the assumption the system is off and will not
communicate with the gauge.
- SHUTDOWN mode: In this mode, the device is
completely disabled to minimize power consumption and
to
avoid depleting the battery.