BQ40Z50: how to limit charge current

gilles MICHEL40

Intellectual 410 points

Part Number: BQ40Z50
Other Parts Discussed in Thread: BQ40Z60, BQ24610

We design a BQ40Z50 board to support a 3.35A pack (4 cells).

Set of registers seems to be correct following guide R3

Charge and discharge works.

But there is a subject that surprise me.

As we have set registers to do a charge at 1650mA @ 4v2 max, we see that the current goes up to 1950mA.

And more precisely, if we increase the current capability deliver by the PS, the current charge varie with the current deliver by the PS.

Sure that we miss something but where !!

Regards

Gilles

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

hi Gilles
The gauge only controls informs the charge on the charge and discharge currents. You need to check your charger to undestand why it is providing more current that is needed. If you configured the gauge for jeita charging, review the charge portion of the data memory registers
thanks
Onyx

0 gilles MICHEL40 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 410 points

Hi Onyx,

Do you have a recommendation for a charger IC ? bq24xxx , bq25xxx

Our battery pack is : 4 cell Li 4S1P @3.3Ah from LGCHEM ref : INR18650_F1L

Thanks

Gilles

0 gilles MICHEL40 over 6 years ago in reply to Onyx Ahiakwo

Intellectual 410 points

Hi Onyx,

In our case, the solution based on Bq40z60 (that include a charger) seems to be a better answer !

instead of Bq40z50 + Bq24610.

Your opinion ?

0 Onyx Ahiakwo over 6 years ago in reply to gilles MICHEL40

TI__Guru* 76230 points

If that is your preference then perhaps you could go with that. Personally, I would opt for the discrete s solution.

thanks
Onyx

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BQ40Z50: how to limit charge current