Battery Management System Design

[arthurartmaster]

Hi all

I am in the process of designning a battery measurement and balancing system I was thinking of using a TI BQ76930, I am following the design guidelines found on pages 4-7 (**broken link removed**). The main issue I am having with this design is identifiying the following properties I am not entirely sure if these are decided by myself or are figures that need to be calculated.
The following is the batteries I am thinking of using: **broken link removed** (For this battery pack I will be using 40 batteries, there will be 4 batteries in parallel and then 10 of these parallel batteries in series to provide 36V and 12Ah). The properites I am unsure mainly came up when decideding the current sensing resistor on page 4: SCD and OCD, for these parameters they have a current, time and threshold voltage, I am not sure where I get this information for the batteries I am using. Another property I am unsure of is the balancing current I should be using can anyone direct me as to what current I should typically use to balance?

Any help and guidance would be greatly appreciated.

Kind Regards

Art

 

[audioguru]

The ad does not say the battery is a Lithium-ion type, but the datasheet does.
Why the warning about 20A? The little Li-PO batteries in my radio controlled model airplanes can produce more current than that.

Your battery will be 36V only when it is about half-discharged. it will be 42V when fully charged and 25V when it is dead.