BQ34Z100-G1: SoC and SoH with Battery Management Stduio program using BQ34Z100-G1

Faruk Sözüer

Intellectual 600 points

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: GPCCHEM

Hi everyone;

My using battery is Kokam Lithium Polymer. It is;

-Capacity = 27000mA

-Number of Cell = 6

Other setting in Program:

-Design Energy Scale = 25

-Design Energy = 27000 * 25.2 = 675000 mWh / 25 = 27000 mWh --> (Capacity * Max Voltage) / Design Energy Scale ---- Is this correct?

-VOLTSEL and SCALED bits are High(1).

-VoltageDivider = 31550 (Found by trial and)

-Flash Update OK Cell Volt = 2981 mVolt --> Calculated according to the formula in Datasheet Page 50 Section 8.2.2.1.3 Step 3.

According to the above values, voltage, current internal and external temperature can be read correctly. But I can not read SoC and SoH values. I have reviewed and implemented the link.

The VOLTSEL bit was not red, which allowed the return of the corresponding bit result in the Alert Configuration.

How do I read SoC and SoH values? Thanks for helping.

over 7 years ago

0 Bryan Kahler over 7 years ago

TI__Mastermind 25955 points

Hi User5076754,

It is recommended to only scale by a value between 1 and 10 to optimize resoultion and accuracy while stil extending the data range. The For ease of use, the Design Energy Scale should normally be 1 or 10 to convert from mWh to cWh.

Please note:
Changing the design energy scale to be >1 requires modification of the units listed in Table 15 of the datasheet: www.ti.com/.../bq34z100-g1.pdf

The calculation for design Energy should be:

Design Capacity = 1 cell capacity * # of parallel cells

Design Energy = Design Capacity * Design Voltage of 1 cell / Design Energy Scale

Normally, batteries with a maximum of 4.2 V have a 3.6 V design capacity.

For a 6s1p configuration where 1 cell has a capacity of 27 A and a nominal voltage of 3.8 V

Design Capacity = 27000 mAh * 1 = 27000

Design Energy = 27000 * 3.6 / 10 = 9720

If the capacity increases slightly more, it may be useful to utilize the current scaling as described in this app note:

www.ti.com/.../slua760.pdf

If your SOH and SOC issues still persist, please update this thread.

Sincerely,
Bryan Kahler

0 Faruk Sözüer over 7 years ago in reply to Bryan Kahler

Intellectual 600 points

Hi Bryan Kahler. Thanks for helping. My problem is still going on. I'm not sure if the Chemistry ID is correct. I do not even know how to do it.
What is the effect of Chemistry ID on the system?
http://www.ti.com/tool/GPCCHEM

0 Bryan Kahler over 7 years ago in reply to Faruk Sözüer

TI__Mastermind 25955 points

Hi Faruk,

You're right on target. The system relies on the proper chemID to have the proper chemical model for the cell. Please use the gpcchem tool to determine the proper chemID for your battery cell.

Since you are using a Lithium Polymer cell, please follow the instructions given in the gpcchem documentation, but instead rest for 5 hours after charge and for 5 hours after discharge as well.

Only a single need needs to be used for creating them chemID, but the series stack may be used as well.

Sincerely,
Bryan Kahler

0 Faruk Sözüer over 7 years ago in reply to Bryan Kahler

Intellectual 600 points

Hi Bryan,

I did my essays and got to the conclusion.

Thank you for your help.

But I have a question. Will we repeat this process for each new BMS? For example, I want to design 10 pieces from this product. Will we do this separately for each battery? (same model of the pillars). Or do I just have to do it once and get a golden image?

Sincerely,

Faruk Sözüer

Power management

Power management forum

BQ34Z100-G1: SoC and SoH with Battery Management Stduio program using BQ34Z100-G1