BQ40Z80: Question about power regulation during charge

Ivo K

Part Number: BQ40Z80

Hi!

I have a question regarding charging control. Gauge has internal registers called Charging Current and Charging Voltage. Their value changes according to current charge region as far as I understand.

I have a question about Charging Voltage, at which point that needs to supplied, is it pack voltage or cell sum? Or maybe some theoretical value...

Which parameter is more critical?

I don't have powerful enough charger should I try to follow voltage or ignore voltage and supply maximum charge current which is still less than Charging Current register requested?

THx

Ivo

over 5 years ago

0 Onyx Ahiakwo over 5 years ago

TI__Guru* 76230 points

Hi Ivo,

Pls reference the EVM user guide for set up instructions. I believe this document addresses your questions

thanks

Onyx

0 Damian Lewis over 5 years ago

TI__Mastermind 34775 points

Hello Ivo,

Please read the app note on Li-ion battery-charger solutions for JEITA compliance

http://www.ti.com/lit/an/slyt365/slyt365.pdf

Charging voltage is always applied at the pack, but the spec prohibits the cell from being charge above the specified voltage and/or current. The gauge would inhibit charging by opening the charge FET if any of the conditions is violated.

Both are important and can be checked individually. If your supply can't generate the max charge current you can lower the max current value for the purpose of test, but remember to readjust it after, else it may impact other testing unintentionally.

0 Ivo K over 5 years ago in reply to Damian Lewis

Prodigy 240 points

Thank you! I will need to experiment and study more, as this question is more related to li-ion battery charging per se than gauge.

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BQ40Z80: Question about power regulation during charge