BQ79606-Q1: how to select the battery Balance current?

Hi Ren,

The balance current needed is typically decided by the end application. For instance, in an application with good quality cells and long charge/idle times, the balancing current can be low as the voltage differences will be smaller and the balancing time is not as big of an issue.

For applications where cells have greatly different SoC/SoH for each cell (more typical of used cells) and where charging/discharging cycles are fast, higher balancing current may be needed to even out the cell voltages quickly.

So the best way to determine balance current required is to figure out the typical charge time, along with the SoH of your batteries, and determine how quickly you will need the cell voltages to be balanced.

Cost can also be a factor however, as higher currents typically require higher BOM cost.

Also, here's a link to a pretty great resource on cell balancing: www.ti.com/.../Topic 2 - Battery Cell Balancing - What to Balance and How.pdf

Regards,
Vince