Rainbow Electronics DS2781 - Manual (Page 17)

DS2781: Two-Cell Standalone Fuel Gauge IC
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between 100% and 50% with a resolution of 61ppm (precisely 2 -14 ). Though the register format permits values
greater than 100%, the register value is clamped to a maximum value of 100%.
Active Empty, AE(T) [ ]: The Active Empty capacity of the battery at the present temperature is reported
normalized to the 40°C Full value. This 13-bit value reflects the cell stack model Active Empty at the given
temperature. AE(T) reports values between 0% and 49.8% with a resolution of 61ppm (precisely 2
-14 ).
Standby Empty, SE(T) [ ]: The Standby Empty capacity of the battery at the present temperature is reported
normalized to the 40°C Full value. This 13-bit value reflects the cell stack model Standby Empty value at the
current temperature. SE(T) reports values between 0% and 49.8% with a resolution of 61ppm (precisely 2
-14 ).
Remaining Active Absolute Capacity (RAAC) [mAh]: RAAC reports the capacity available under the current
temperature conditions at the Active Empty discharge rate (IAE) to the Active Empty point in absolute units of milli-
amp-hours. RAAC is 16 bits.
Remaining Standby Absolute Capacity (RSAC) [mAh]: RSAC reports the capacity available under the current
temperature conditions at the Standby Empty discharge rate (ISE) to the Standby Empty point capacity in absolute
units of milli-amp-hours. RSAC is 16 bits.
Remaining Active Relative Capacity (RARC) [%]: RARC reports the capacity available under the current
temperature conditions at the Active Empty discharge rate (IAE) to the Active Empty point in relative units of
percent. RARC is 8 bits.
Remaining Standby Relative Capacity (RSRC) [%]: RSRC reports the capacity available under the current
temperature conditions at the Standby Empty discharge rate (ISE) to the Standby Empty point capacity in relative
units of percent. RSRC is 8 bits.
Calculation of Results
RAAC [mAh] = (ACR[mVh] - AE(T) * FULL40[mVh]) * RSNSP [mhos]
RSAC [mAh] = (ACR[mVh] - SE(T) * FULL40[mVh]) * RSNSP [mhos]
RARC [%] = 100% * (ACR[mVh] - AE(T) * FULL40[mVh]) /
{(AS * FULL(T) - AE(T)) * FULL40[mVh]}
RSRC [%] = 100%* (ACR[mVh] - SE(T) * FULL40[mVh]) /
{(AS * FULL(T) - SE(T)) * FULL40[mVh]}