BQ29200: BQ29200 balancing in sleep mode (not charging)

Daniel Waleniak

Part Number: BQ29200

Dear Team,

My customer wants to use BQ29200 in a system, where their device is spending most of the time in sleep mode. However, they have a system with a 2 cell battery, where the cells are unevenly loaded. In sleep mode the first cell has a current draw of 280uA and the second only about 11uA, which means a 30mV imbalance after some time in sleep mode.

As long as the BQ29200 is enabled by grounding the EN pin, can you confirm that the cell balancing will also happen in deployment where the end device is spending most of its time in sleep mode?

It seems that BQ29200 is a rather simple device and should always perform the balancing as long as enabled even when not charging, but please confirm.

Thanks,

Daniel

over 1 year ago

0 Maxwell Verboncoeur over 1 year ago

TI__Mastermind 19830 points

Hi Daniel,

It should not matter if your customer's end device is in sleep mode or not. As long as there is sufficient imbalance in the cell voltages and balancing is enabled on the BQ29200, the balancing will activate.

Regards,

Max Verboncoeur

0 Daniel Waleniak over 1 year ago in reply to Maxwell Verboncoeur

TI__Expert 4545 points

Hello Max,

Thanks for the confirmation. Can you also please take a look at the following:

+1 Maxwell Verboncoeur over 1 year ago in reply to Daniel Waleniak

TI__Mastermind 19830 points

Hi Daniel,

Your schematic seems good.

One thing to bear in mind is your external balancing current can get up to around 200mV (4.35V / 22ohms = ~198mA, 4.35V being the OVP threshold and 22ohms being the balancing resistor.)

I would double check to make sure this is what you want and that your components are rated to handle it.

Regards,

Max Verboncoeur

Power management

Power management forum

BQ29200: BQ29200 balancing in sleep mode (not charging)