AN2309
November 25, 2007
Document No. 001-17394 Rev. *B
- 15 -
The minimum cell-balance parameter consists of the voltage measure error value plus the internal impedance error value.
The cell-balancing algorithm that is implemented here does not significantly lengthen the charge time. The charger monitors all
of the cell voltages. Cell balancing is performed during both phases and it is realized in one common module. The cell-
balancing algorithm is represented in
Figure 11
. The cell-balancing profile examples are shown in the Appendix,
Figure 14
on
page 19 and
Figure 15
on page 20.
Figure 11. Cell-Balancing Algorithm
Start
Chagre Off
Balancing Reset
DoCellBalancing = FALSE
Wait Start Delay
Send Debug Data
Are cells Not
Balanced?
V
bmax
-V
bmin
>dV
ch_balmin
No
Measure V
b1
, V
b2
Calc V
bmin
, V
bmax
, dV
Check Out Of The
Minimum Cell
Balancing Current
isCV and I
ch
<I
balmin
Yes
No
Yes
End
Chagre On
Wait End Delay
Is Discharge State?
No
Yes
Are Cells Not
Balanced?
V
bmax
-V
bmin
>
dV
disch_balmin
No
Check Out Of
The VMID Voltage
V
bmax
<V
mid
Yes
No
DoCellBalancing = TRUE
Yes
DoCellBalancing = TRUE
Is DoCellBalancing?
Yes
V
b1
>V
b2
Yes
No
Balancing Cell 1
Balancing Cell 2
No
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