bq34z100 - applying QMax0 and CC threshold

Peter Upczak

Other Parts Discussed in Thread: BQ34Z100-G1

I'm still not 100% sure of the applied range for these parameters, even though the forums suggest each in various contexts:

QMax0 - per cell (series) or per battery-pack (parallel) ?

CCThreshold - per cell (series) or per battery-pack (parallel) ?

I'm asking now, because my most recent optimizations are resulting in charge % values that don't track, but current and voltage readings are very close to measured.

thanks,

over 9 years ago

0 ThomasCosby over 9 years ago

TI__Guru 73830 points

Qmax is always at the 1S level. The gauge will lump parallel cells as one cell, so the capacities for parallel cells will be added. If you have a 1000mAh cell in a 4S1P configuration, then set Qmax to 1000mAh. If you have a 3S4P configuration, then set Qmax to 4000mAh.

The CCThreshold will be set in the same manner. People usually set it to 90% to 100% of the FCC value, but it will not affect you optimization cycle results.

0 Peter Upczak over 9 years ago in reply to ThomasCosby

Intellectual 965 points

Excellent. Thanks!

0 user4801823 over 8 years ago in reply to ThomasCosby

Prodigy 80 points

If I have a 1000mah 3s1p , the Qmax is still 1000mAh？ If it is a 1000mAh 4s 4P, the Qmax is still 4000mAh? The voltage don't effect of the Qmax?

0 ThomasCosby over 8 years ago in reply to user4801823

TI__Guru 73830 points

Your Qmax estimates are correct. Qmax is defined at a 1S level, where Design Energy is at that pack level. Design Energy = Design Capacity x Design Voltage.

0 ThomasCosby over 8 years ago in reply to ThomasCosby

TI__Guru 73830 points

Allow me to make a correction. The Design Energy is reported at the pack level for most gauges, but the bq34z100-G1 handles all internal calculations at the cell level and the Design Energy is also reported and entered at the 1S level.

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bq34z100 - applying QMax0 and CC threshold