Rainbow Electronics DS2778 User Manual
Page 23
DS2775/DS2776/DS2777/DS2778
2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
Protector and Optional SHA-1 Authentication
______________________________________________________________________________________
23
The RAAC register reports the capacity available under the current temperature conditions to the the active-empty
point in absolute units of milliamps/hour (mAh). RAAC is 16 bits.
The RSAC register reports the remaining battery capacity available under the current temperature conditions to the
standby-empty point capacity in absolute units of milliamps/hour (mAh). RSAC is 16 bits.
The RARC register reports the remaining battery capacity available under the current temperature conditions to the
active-empty point in relative units of percent (%). RARC is 8 bits.
The RSRC register reports the remaining battery capacity available under the current temperature conditions to the
standby-empty point capacity in relative units of percent (%). RSRC is 8 bits.
Calculation of Results
RAAC [mAh] = (ACR[mVh] - AE(T) x FULL40[mVh]) x RSNSP [mhos]*
RSAC [mAh] = (ACR[mVh] - SE(T) x FULL40[mVh]) x RSNSP [mhos]*
RARC [%] = 100% x (ACR[mVh] - AE(T) x FULL40[mVh])/{(AS x FULL(T) - AE(T)) x FULL40[mVh]}
RSRC [%] = 100% x (ACR[mVh] - SE(T) x FULL40[mVh])/{(AS x FULL(T) - SE(T)) x FULL40[mVh]}
*
RSNSP = 1/R
SNS
MSB—ADDRESS 02h
LSB—ADDRESS 03h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
MSb
LSb
UNITS: 1.6mAh
Figure 16. Remaining Active Absolute Capacity (RAAC) [mAh]
MSB—ADDRESS 04h
LSB—ADDRESS 05h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
MSb
LSb
UNITS: 1.6mAh
Figure 17. Remaining Standby Absolute Capacity (RSAC) [mAh]
MSB–ADDRESS 06h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
MSb
LSb
UNITS: 1%
Figure 18. Remaining Active Relative Capacity (RARC) [%]
MSB–ADDRESS 07h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
MSb
LSb
UNITS: 1%
Figure 19. Remaining Standby Relative Capacity (RSRC) [%]