BQ40Z80: Minimal external cell balancing circuit

SAERO

Part Number: BQ40Z80

Hello,
We have been using BQ40Z80 with internal cell balancing for quite some time now. We'd like to implement external cell balancing and circuit on datasheet, and few forum posts look quite different. It'd be great if someone can share minimal circuit to get external cell balancing. Found below from forum.

Thank you!

over 2 years ago

0 Wyatt Keller over 2 years ago

TI__Guru** 105760 points

Hello Saero,

This is the correct configuration for external cell balancing, I would implement your balance schematic based on this example.

Sincerely,

Wyatt Keller

0 SAERO over 2 years ago in reply to Wyatt Keller

Intellectual 361 points

Ti technical manual shows this setup. The 100nF can connect to GND or adjacent cell? Both will work? Also the cell FET is N-ch or P-ch? Do suggest anything particular points to follow for 6S setup?
Thank you!

+1 Wyatt Keller over 2 years ago in reply to SAERO

TI__Guru** 105760 points

Hello Saero,

I would recommend following the image you attached first, use caps between each cell. The images show which FETs are P or N channel.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z80: Minimal external cell balancing circuit