Please help identifying balancing wires on li-ion laptop battery

[jmsprof]

Hello.

Problem

Please can you help me identify the balancing wires on a 3 cells laptop battery. Total tension is 12.5V when fully charged.

Assuming the battery/cells are balanced, each cell is ~4.16V. So when measuring tension between different wires, I should get ~4.16V (between B- and B1 or between B+ and B2), and ~8.32V (between B- and B2 or between B+ and B1).

However I get nowhere near these values. I get either values that are too heigh (9.15 or 10.07V) or too low (2.83, 2.95, 3.16, or 3.28V).

Background

The battery come from a Toshiba Chromebook 2 laptop, with a 10.8V li-ion battery (3 cells).

Battery is:
http://www.laptop-battery-shop.com/toshiba-pa5208u1brs-108v-3860mah-original-batteries-p-5298.html

The battery has 9 wires:

1 and 2 are both RED, and are the +ve end of the battery (B+). Given this, I have not measured from wire 1, as it is the same as wire 2.

8 and 9 are both BLACK, and are the -ve end of the battery (B-). Given this, I have not measured from wire 9, as it is the same as wire 8.

1-2 : RED
3 : Yellow
4 : Blue
5 : White
6 : Green
7 : Orange
8-9: BLACK

** Here are the tensions between the different wires: **

FULLY CHARGED BATTERY (37Wh):

Between wires:

2-3: 0.13 V
2-4: 12.48 V
2-5: 12.07 V
2-6: 9.15 V
2-7: 9.15 V
2-8: 12.48 V

3-4: 3.16
3-5: 2.83
3-6: 0
3-7: 0
3-8: 3.16

4-5: 0.30
4-6: 3.28
4-7: 3.28
4-8: 0

5-6: 2.95
5-7: 2.95
5-8: 0.30

6-7: 0
6-8: 3.28

7-8: 3.28

EMPTY BATTERY (1.5Wh):

Between wires:

2-3: 0.13 V
2-4: 10.08
2-5: 9.72
2-6: 6.77
2-7: 6.77
2-8: 10.08

3-4: 3.16
3-5: 2.84
3-6: 0
3-7: 0
3-8: 3.16

4-5: 0.30
4-6: 3.28
4-7: 3.28
4-8: 0

5-6: 2.95
5-7: 2.95
5-8: 0.30

6-7: 0
6-8: 3.28

7-8: 3.28

Thank you!

[Author]

Posts