![background image](http://html1.mh-extra.com/html/texas-instruments/bq27441-g1/bq27441-g1_technical-reference_1095321048.webp)
bq27441 Data Memory Parameter Descriptions
6.4.3 Ra Table Class
6.4.3.1
R_a RAM Subclass
Subclass
Subclass
Offset
Name
Type
Value
Unit
ID
Min
Max
Default
R_a RAM
89
0
R_a0 0
I2
0
32767
-G1A = 102
Num
-G1B = 16
2
R_a0 1
I2
0
32767
-G1A = 102
Num
-G1B = 17
4
R_a0 2
I2
0
32767
-G1A = 99
Num
-G1B = 20
6
R_a0 3
I2
0
32767
-G1A = 107
Num
-G1B = 24
8
R_a0 4
I2
0
32767
-G1A = 72
Num
-G1B = 20
10
R_a0 5
I2
0
32767
-G1A = 59
Num
-G1B = 18
12
R_a0 6
I2
0
32767
-G1A = 62
Num
-G1B = 20
14
R_a0 7
I2
0
32767
-G1A = 63
Num
-G1B = 20
16
R_a0 8
I2
0
32767
-G1A = 53
Num
-G1B = 21
18
R_a0 9
I2
0
32767
-G1A = 47
Num
-G1B = 22
20
R_a0 10
I2
0
32767
-G1A = 60
Num
-G1B = 24
22
R_a0 11
I2
0
32767
-G1A = 70
Num
-G1B = 31
24
R_a0 12
I2
0
32767
-G1A = 140
Num
-G1B = 49
26
R_a0 13
I2
0
32767
-G1A = 369
Num
-G1B = 98
28
R_a0 14
I2
0
32767
-G1A = 588
Num
-G1B = 375
The Ra Table class has 15 values. The R_a RAM is initialized from ROM upon gauge reset. Each of these
values represents a resistance value normalized at 25°C for the associated Qmax Cell 0-based SOC grid
point as found by the following rules:
For Cell0 Ra M where:
•
If 0
≤
M
≤
7: The data is the resistance normalized at 25° and scaled by
Design Capacity
or
Default
Design Cap
for:
SOC = 100% – (M × 11.1%)
•
If 8
≤
M
≤
14: The data is the resistance normalized at 25° and scaled by
Design Capacity
or
Default
Design Cap
for:
SOC = 100% – [77.7% + (M – 7) × 3.3%]
This gives a profile of resistance throughout the entire SOC profile of the battery cells concentrating more
on the values closer to 0%.
48
Data Memory
SLUUAC9A – December 2013 – Revised May 2015
Copyright © 2013–2015, Texas Instruments Incorporated