BQ25890: Chargin curve question

Edgar Lin2

Prodigy 210 points

Part Number: BQ25890

We are uging BA25890 for charging 6600mAh battery.

The DCP adapter rated power is 5V/3A.

Below is our charing curve.

We can see the curve of CV mode is very stranger.

Is it normal? If not, please help me to solve this issue.

Thanks.

Edgar

over 3 years ago

0 Garrett Kreger over 3 years ago

TI__Mastermind 32030 points

Hi Edgar,

In general the curve looks alright and follows the expected behavior of charge current reducing. In reality the charge current in CV mode will not be the smooth decay shown in figure 13 in the datasheet.

Regards,

Garrett

0 Edgar Lin2 over 3 years ago in reply to Garrett Kreger

Prodigy 210 points

Hi Garrett

If I would like to see the charging current smooth decay in CV mode, how to adjust the value of register 0x08.

Thanks

Edgar

0 Garrett Kreger over 3 years ago in reply to Edgar Lin2

TI__Mastermind 32030 points

Hi Edgar,

Can you please share with me your current register settings? The CV decay you are seeing may be related to settings on REG08.

Regards,

Garrett

0 Edgar Lin2 over 3 years ago in reply to Garrett Kreger

Prodigy 210 points

Hi Garrett
Below is our register setting.

Beside, the termination current we set is 128mA, but from the guage log ,it will stop charging at 178~ 182mA.

Please also help on this promble.

Thanks

Edgar

0 Garrett Kreger over 3 years ago in reply to Edgar Lin2

TI__Mastermind 32030 points

Hi Edgar,

To see smooth decay in the CV phase of charge you will need to turn off IR compensation by adjusting REG08 to = 0 (00000000)

Regards,

Garrett

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BQ25890: Chargin curve question