BQ25890H: Modification of the JEITA maximum temperature profile

Philippe PORTE

Prodigy 10 points

Part Number: BQ25890H
Other Parts Discussed in Thread: BQSTUDIO

Hello,

We have designed a portable device with BQ25890H to charge a Lithium battery.

We must customize the JEITA Profile T5 temperature to 45°C.

Because our new battery cells accept only a charge at maximum 45°C.

Is it possible to do this?

Or if it is not, is it possible to change some components values of the BQ25890H to stop the charge at 45°C?

If we change the value of RT1 and RT2 to define a maximum at 45°C with R_HOT = 4.92KOhms.

Do you think it is possible?

But in this case, the COOL and WARM threshold will be not at 10°C and 40°C. Is it possible to adjust these parameters?

Thank you in advance for your help.

over 2 years ago

0 Wyatt Keller over 2 years ago

TI__Guru** 102405 points

Hello Philippe,

If you wish to disable charge at 45°C you will need to adjust the RT1 and RT2 values so T5 is 45°C. But as you mentioned the warm and cool temperature thresholds will also move, there's nothing we can do for this because it is a preset value as a percent of REGN.

This tool can help you confirm RT1 and RT2 calculations: www.ti.com/.../slurax7

Sincerely,

Wyatt Keller

0 Philippe PORTE over 2 years ago in reply to Wyatt Keller

Prodigy 10 points

Hello Wyatt,

Thank you for your answer.

Other question, is it possible to save the parameters in the BQ25890H. Because if we change the battery, we restart with default parameters.

Regards,

Philippe

+1 Wyatt Keller over 2 years ago in reply to Philippe PORTE

TI__Guru** 102405 points

Hello Philippe,

You can save the registers in bqStudio as a text file, but there is no way to save them in the charger because it does not have flash memory.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ25890H: Modification of the JEITA maximum temperature profile