BQ4050: Using 100K Thermistor

Christopher Kim

Part Number: BQ4050

Hello,

I am currently working with the BQ4050 gas guage to monitor the charging status of two 1S series Lithium-ion polymer batteries with built in 100K thermistors. I know the datasheet mentions that the BQ4050 expects to see a 10k thermistor, which explains the temperature values that I'm seeing on the BQ Studio software. Is there any way to properly scale these temperature results or change the settings to adjust for the 100k thermistor?

Thanks,

Chris

over 6 years ago

0 Kang Kang over 6 years ago

TI__Mastermind 24870 points

I would recommend to use the 10K NTC recommended by EVM UG and datasheet.

0 Christopher Kim over 6 years ago in reply to Kang Kang

Prodigy 20 points

Hi Kang,

Is there no work around to be able to use the 100K NTC that's already built into the battery pack?

Thanks,
Chris

0 Swaminathan Ramanathan75031 over 6 years ago in reply to Christopher Kim

TI__Expert 6575 points

Hi Chris,
You can use the temperature coefficient calculator at e2e.ti.com/.../bq40xxxx-family-Thermistor_5F00_Coef_5F00_Calculator.xlsx to see if the 100k NTC will work, but I suspect that the coefficients might be out of range for an NTC that is an order of magnitude larger.
I would strongly recommend selecting a 10k NTC though.
Regards,
Swami

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BQ4050: Using 100K Thermistor