BQ28Z610: Ways to provide constant charge/discharge current for Learning Cycle

Hello Shirish,

For charge termination I assume you're referring to the green part of the Learning Cycle on this graph, right?

If so, for this battery, I should simply perform the green part following the battery's datasheet parameters for charging:

Charge using a constant current of 1625mA, constant voltage of 4.2V, and leave charging until the charge current drops down to 65mA, right?

Thanks again!

Ed

Hello Shirish,

Now for charging, my battery circuit already uses one of the ICs of the link you gave. Its the BQ25883 (I2C 2 cell 2A Boost battery charger for USB input). This is the circuit:

So can I perform the Charge Termination (green part) of the Learning Cycle using this charger that's already on my circuit? Note that my battery circuit uses 2 batteries.

Thanks Shirish, I'll do this then: Perform the Charge Termination part using the BQ25883 charger IC that's already on my circuit shown above.

Now, for both discharge parts (initial discharge and the discharge with I > C/10), I assume it must be done using an external load.

I see on the Learning Cycle PDF:

But it's not clear to me if there are ways to do this using the charger or gauge ICs, without an external load.

So, to confirm:

I must perform both discharge parts of the Learning Cycle by draining a constant current from the batteries, and drain this current through the charger and the gauge ICs, like a normal load attached to my battery manager circuit, right?

(I understand this current needs to be drained only through the gauge IC for the Learning Cycle, but the charger IC is between the gauge and the load output of the circuit)

The load must be connected to Pack+ and Pack-.

Isn't the charger removable?

No, but I can make a cut on the PACK+ trace that goes to the BAT pin of the charger, and place the load there for the discharge parts. Then jump it back for the charge part, if that's an option.

Yes, I'll do that then. I found a way to disable charging on my charger IC. So I'll disable charging for all stages of the Learning Cycle except "charge termination".

Now, my charger IC has a trickle-charge and pre-charge steps before the normal charging step.

Can I still do the "charge termination" stage of the Learning Cycle with trickle charge and pre-charge before the normal charging?