Other Parts Discussed in Thread: BQSTUDIO
Tool/software:
Hi, Team
My customer use BQ4050 in one of the battery pack and they have a question about the current balancing, could u help to check and give your comments as below?:
Customer have a 2P3S Lifepo4 pack and are concerned with balancing, so they want to optimize the setting for the best balancing ability.
Here is the current setting they are looking at.
|
Setting |
Value |
|
Cell Balance Threshold |
3350 mV |
|
Cell Balance Min |
25 mV |
|
Cell Balance Window |
25 mV |
|
Cell Balance Interval |
20 sec |
|
Balance Capability |
20 mA |
|
2P Total Capacity |
10000 maH |
|
Cell OVP |
3650 mV |
|
Full Charge Float Voltage |
3.6V/Cell, 10.8V/PACK |
|
System CC setting |
0 ~ 10deg 0.2C |
|
|
15~50deg 0.4C |
Here is the battery charge curve for SOC vs voltage, note that as customer have a small balancing current and a 2P3S pack using large 5000mah cells, they would like to have the balancing enabled for as much of the curve as possible.
Note that if they start to balance around 3350mV, it should be active for about 2/3 of the charge time. In this case lets say about 2h.
For 2h under balance 2h * 20ma / 10000mah = 0.4% Balance capability per change cycle which is probably OK.
Does this seem a reasonable way to set the gauge based on these cells?
Pls share your comments to customer for this concern.
Thanks.
G.W
