BQ27531-G1: Design capacity value

Alexandru Mixich

Part Number: BQ27531-G1

Hi,

we are using in our project the BQ27531-G1 to track the remaining capacity of the battery. The battery has a capacity of 4400 mAh. Due to some safety reason we charge with 4.1V (and not 4.2V as required to achieve the full capacity) and I'm just wonder which value to set in the register "Design Capacity". Should I set 4400mAh or another value (i.e. 4200mAh)?

Regards,

Alex

9 months ago

+1 Anthony Baldino 9 months ago

TI__Genius 13495 points

Hi Alex,

If you are performing the learning cycle for the gauge, you should set the design capacity to the battery's nominal capacity (4400mAh). Once the learning cycle has been preformed, the Design Capacity can be changed to the target value for the application.

Below is Section 2.1 from the Achieving the Successful Learning Cycle document:

https://www.ti.com/lit/pdf/slua903

Regards,

Anthony Baldino

0 Alexandru Mixich 9 months ago in reply to Anthony Baldino

Intellectual 485 points

Thank you Anthony for the good explanation!!

0 Alexandru Mixich 9 months ago in reply to Anthony Baldino

Intellectual 485 points

One question i still have. If we change the charge voltage from 4.4V to 4.1V how it will affect the taper current. Should i set a slightly higher or lower as it was set during the learning cycle?

Regards,

Alex

0 Anthony Baldino 9 months ago in reply to Alexandru Mixich

TI__Genius 13495 points

Hi Alex,

If you are lowering the charge voltage, you can slightly decrease the taper current, but it should not affect the performance by much.

Regards,

Anthony Baldino

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BQ27531-G1: Design capacity value