BQ40Z60: Max Battery capacity

Ondrej Bures

Part Number: BQ40Z60
Other Parts Discussed in Thread: BQ40Z50-R2, , BQ40Z50, BQSTUDIO

Hello dear TI.

I would like to use this chip in my project (school project), where will be 4 serial cells. in each cell will be 4 li-ion battery 18650 with capacity 3000 mAh connected paralel.

I found on this page -> http://www.ti.com/product/BQ40Z60/description What can happen, if i connect there (4*4*3000 = 48000) 48000 mAh battery? The battery Gauging won't go properly ? Becouse in datasheet i didnt found anything about max capacity.

Thanks for any help

over 7 years ago

0 TEC over 7 years ago

Expert 2475 points

You should not exceed 29Ah capacity on Impedance Track gauges, because calculation overflows in firmware could potentially occur. You can use capacity scaling to support higher capacity packs and the attached applications brief can help. Is there a reason why you are using the bq40z60? The bq40z50-R2 will provide better performance.

5086.High cell count app note.pdf

0 Ondrej Bures over 7 years ago in reply to TEC

Prodigy 140 points

Thank you very much for your reply.

Well, there's no reason why I'm using bq40z60. So I will use bq40z50.

Is there any tutorial, how to do that? I read that pdf, and I know what to do, but I really do not know how.

If I understand that, I will connect bq40z50 to PC, download bqstudio and then edit configuration and send it to flash memory. Right ?

I am realy sorry for my stupid questions. I am totaly new in this power management.

Thank you.

0 TEC over 7 years ago in reply to Ondrej Bures

Expert 2475 points

The bq40z50-R2 datasheet and bq40z50EVM User's Guide have design examples that should help you. I attached a presentation that was given at a BMS Deep Dive event that should help to better understand capacity scaling.

2015_DD_Gauge Design Configurations for High Charge Discharge Rate Applications.pdf

0 Ondrej Bures over 7 years ago in reply to TEC

Prodigy 140 points

Thank you very much for reply :) !

Yeah it helped !

Power management

Power management forum

BQ40Z60: Max Battery capacity