OV, UV, OCP, monitoring & balancing solution for 16 cell series / 48V / LiNiMnCoO2

Ahmad_Rashed

Other Parts Discussed in Thread: BQ76PL536A, BQ76920, BQ76PL455A, BQ40Z50-R1

Hello BMS Experts,

I'm working with a customer on a BMS based on 16 series cells (partitioned into 4 packs of 4 cells). The cell chemistry is LiNiMnCoO2.

What ICs can possibly support this set-up? I'm looking at BQ76PL536A for each pack of 4 cells which does the over voltage and under voltage but no OCP.

For over current protection would this call for the BQ76920 instead?

Thanks in advance.

over 9 years ago

0 Roger Hwang over 9 years ago

TI__Genius 10785 points

We don't have 16S solution with all the options you need.
Bq76pl455A is 16S but it doesn't have OCP as bq76pl536A.

You can't stack bq76920. It may be possible with isolation circuits.

Is it 4 packs stacking? or, is it 4S 4P, 16S1P.

you have to have your own OCP circuit if you choose PL536A or PL455A.

0 Ahmad_Rashed over 9 years ago in reply to Roger Hwang

TI__Genius 13567 points

So the cells are 4 in series to make a 12V pack. Then those are then put in series for a 48V pack.

Could you tell me more about the BQ76920? They say it is okay that there is no communication between packs. What would the isolation circuitry look like?

0 Roger Hwang over 9 years ago in reply to Ahmad_Rashed

TI__Genius 10785 points

I will send you separate email.

0 Ahmad_Rashed over 9 years ago in reply to Roger Hwang

TI__Genius 13567 points

Thanks for the email. Another IC that I am looking at is the BQ40Z50-R1. But it seems to be meant for laptop batteries. Could this IC be dedicated to managing 4 cells on its own to make one 12V pack. Then have 4 of these packs work in series? The customer wants 40A continuous current for motor driving so I am not sure if the gas gauge can keep up with that.

0 Roger Hwang over 9 years ago in reply to Ahmad_Rashed

TI__Genius 10785 points

I don't think you can stack Z50 as well but you might want to check out from Gauge team.

I think you should post it to Gauge forums.

Again, you have two options from MnP.

1. Stack bq76920. You can reference to block diagram I sent to you.

2. Use PL536A or PL455A and add OCP function.

Check Z50 option with Gauge team.

Power management

Power management forum

OV, UV, OCP, monitoring & balancing solution for 16 cell series / 48V / LiNiMnCoO2