BQ27421-G1: Speed up entry normal hibernate mode

Beginner

Part Number: BQ27421-G1

Hi Team,

I know there are two hibernate mode - fast and normal.

For FH, we can set specified DF value in FH setting to entry. This is the fastest way to enter hibernate.

For normal, we can set normal DF value in FH setting and trigger by issuing SET_HIBERNATE cmd. It will take up to 1 hours for OCV taken after issuing cmd.

However, Customer is looking forward a way to decrease 1 hours to couple minutes in normal hibernate mode after issuing cmd.

Do we have any way to implement on this?

over 5 years ago

0 Wyatt Keller over 5 years ago

TI__Guru** 105590 points

Hello Beginner,

Let me check with the firmware team.

Sincerely,

Wyatt Keller

0 Wyatt Keller over 5 years ago

TI__Guru** 105590 points

Hello Beginner,

The bq27421-g1 is not designed to go so quickly from normal mode to hibernate mode because it needs the chance to update the OCV and Qmax. Without taking accurate OCV readings the accuracy of the gauge will degrade over time.

Sincerely,

Wyatt Keller

0 Beginner over 5 years ago in reply to Wyatt Keller

TI__Intellectual 2381 points

Supposedly, there are couple FH settings.

For FH settings 2, it seems like used for OCVtaken. Could you decrease these value to see if gauge can entry hibernate mode firstly?

0 Dominik Hartl11 over 5 years ago in reply to Beginner

TI__Guru 61006 points

The gauge will enter hibernate within seconds if you configure it for fast hibernate as described in the TRM, 2.4.6.1.

This will force the gauge to take an open circuit voltage measurement as soon as the state changes to relax, thus it will interfere with proper gauging and must be restored to "normal" hibernate values when you want to resume gauging.

Power management

Power management forum

BQ27421-G1: Speed up entry normal hibernate mode