BQ27542-G1: 1500uA current leak in TI battery gauge

GregoireGentil

Expert 2330 points

Part Number: BQ27542-G1
Other Parts Discussed in Thread: BQSTUDIO

Hello,

I have a standalone / removable battery pack with:

- the battery chemistry, Poly 3.7V one-cell 1000mAh

- a battery protection IC DW01-P from Chinese Fortune

- a battery charger LTC4067 from Linear

- a battery gauge BQ27542.

Without the TI battery gauge BQ27542, the current leak (the current measured at the pin + of the battery chemistry) is around 150 uA.

With the TI battery gauge BQ27542, the current leak is around 1750uA. So BQ27542 is using around 1.5mA which is a lot. It will drain the battery in one month. And it's what I'm seeing.

Is it normal to have such high current leak for BQ27542? Is there a way (software settings) to lower that amount?

PS: I can provide the schematics in a private message.

over 5 years ago

0 Kang Kang over 5 years ago

TI__Mastermind 24870 points

Hello Gregoire,

Sure, please request me as a friend.

You need to check the pull up resistors for comms. It may not be the gauge pulling but other external networks.

0 GregoireGentil over 5 years ago in reply to Kang Kang

Expert 2330 points

You mean the pull-up resistor on the I2C line? There is none in the battery pack. It's on the device side when the battery is inserted.

Also, the current measurement seems pretty accurate as it's done with the "Current Ranger" tool.

0 Kang Kang over 5 years ago in reply to GregoireGentil

TI__Mastermind 24870 points

Okay, I've sent you a message. Closing this thread out.

0 GregoireGentil over 5 years ago in reply to Kang Kang

Expert 2330 points

Hello,

I'm still stuck on this issue and cannot understand why the TI chip BQ27542 leaks so much current.

0 Kang Kang over 5 years ago in reply to GregoireGentil

TI__Mastermind 24870 points

Hello Gregoire,

Can you try the suggestion I made? Send an I2C stop condition?

It would be good if you can capture a bqStudio log to see what mode the gas gauge is in.

0 GregoireGentil over 5 years ago in reply to Kang Kang

Expert 2330 points

I think that we start having the right conversation. I'm investigating some settings but without any success so far. It's worth noting that the battery gauge is not sealed.

0 Kang Kang over 5 years ago in reply to GregoireGentil

TI__Mastermind 24870 points

Hello Greg,

I would really try to get an IC in a fail condition and send an I2C stop condition. I think you are just sending a start and the IC is in a power mode looking for the stop condition.

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BQ27542-G1: 1500uA current leak in TI battery gauge