BQ78350-R1A: Can I get Accurate SOC and SOH for 6P4S - (6Parallel 4 series) battery Pack Lithium-ion

Shashi Rai

Part Number: BQ78350-R1A
Other Parts Discussed in Thread: BQ76920, BQ76907, BQ78350, BQ4050

Hi,

As working on a BMS (Battery Management system) power bank project and have gone through the BQ78350-R1A fuel gauge device.

Need to Know that

1) is it capable to do providing the SOC/SOH data to MCU and can be displayed on LCD/OLED in the form of battery bar-based status as well as battery 1% to 100% indication?

2) As I can check into the datasheet it provides only LED/LCD bar status in 20% each resolution for SOC, is that right ? or we display data in 1% resolution from 1% to 100%?

3) can I connect the Companion controller BQ76920 with lithium-ion 18650 cells in 6 parallel ( to each series cell) and 4 series configurations, Is there any issue in balancing the cells?

please suggest

Thanks and Regards,

Shashikumar Rai

over 1 year ago

0 Dominik Hartl11 over 1 year ago

TI__Guru 61066 points

#1: This gauge can report SOC and SOH to an MCU. It can display SOC on 5 LEDs. Each LED has a configurable SOC threshold.

#2: It can only drive 5 LEDs. The default thresholds are 0/20/40/60/80%.

#3: Yes. It will balance within its limits.

0 Shashi Rai over 1 year ago in reply to Dominik Hartl11

Prodigy 120 points

Hi,

As i can see that, this device supports LCD display for SOC and SOH. so it means it shows only bar form of data resolution on LCD?

From Datasheet

Thanks & Regards,

Shashikumar Rai

0 Dominik Hartl11 over 1 year ago in reply to Shashi Rai

TI__Guru 61066 points

Yes, displays data as a line of dots (bar).

0 Shashi Rai over 1 year ago in reply to Dominik Hartl11

Prodigy 120 points

Hi,

Thanks for the reply.

As in the datasheet of BQ78350-R1A the companion part recommended is BQ769020, Can you please suggest instead of BQ769020 we can use the BQ76907 part.

As BQ76907 have more features then BQ769020 like

1) Flexible configuration for 2- to 7-series

2) Dedicated 16- or 24-bit delta-sigma coulomb counter ADC

3) Multiple power modes (typical battery pack operating range conditions)

– NORMAL mode: 32 μA to 175 μA

– SLEEP mode: 6 μA

– DEEPSLEEP mode: 2.7 μA

– SHUTDOWN mode:

Please suggest.

Thanks & Regards,

Shashikumar Rai

0 Dominik Hartl11 over 1 year ago in reply to Shashi Rai

TI__Guru 61066 points

The bq76907 is not compatible with the bq78350.

TI has combined one chip solutions like the bq4050 (CEDV). https://www.ti.com/product/BQ4050

This may be a better fit for your application.

Power management

Power management forum

BQ78350-R1A: Can I get Accurate SOC and SOH for 6P4S - (6Parallel 4 series) battery Pack Lithium-ion