Hi
We are using the BQ34Z100 with 2 series Li-Ion cells (2900mAh).
The charger we are using (I don't think it can be changed) is a single stage charger that cuts off the charge at 8.4V and does not do the second stage saturation charging down to 50mA.
I am currently tying to "teach" the pack prior to production. The problem is the FC bit doesn't get set when charging.
I've set the taper current to 300mA (the chargers seem to stop around 200-250mA), cell taper voltage to 200mV, taper window to 20s and FC Set to -1.
The pack passes the taper current and taper voltage, but the FC bit is never set.
The datasheet says
"The bq34z100 detects charge termination when (1) during two consecutive periods of Current Taper Window, the
AverageCurrent() is < Taper Current and (2) during the same periods, the accumulated change in capacity >
0.25 mAh /Taper Current Window and (3) Voltage() > Charging Voltage - Charging Taper Voltage."
I don't understand how I can read the second requirment, do I need to adjust Min Taper Capacity? Its set to 25mAh
Is it the case that FC will never be set due to single stage charging?
Can I optimise the settings without FC being set, I thought it was required to update an internal parameter, but perhaps I misunderstood this?
Thanks
Morgan