Other Parts Discussed in Thread: , BQ40Z80, BQ34Z100, BQ34110, BQ78350-R1
Hi:
We were designing a battery fuel gauge application around the BQ40Z50-R2 chip and had the features we wanted pretty well worked out in terms of
- Overcurrent Protection
- Overvoltage
- Undervoltage
But SOC seems to be a problem. I believe this is due to having gauging turned on, and our application is a bit oversized for the BQ40Z50
The application uses 4 cells (3.8V each) with a total capacity of 700 Wh and thus 46 Ah. Discharge output is about 80 A and charge input is up to about 50 A.
- Charge/Discharge Voltage 16.8V
- Typical MOSFET setup with Amplified Cell Balance
I note that particularly the discharge capacity of 46 Ah is well beyond the 29 Ah limit for gauging with the BQ40Z50.
Since we are so far along with the BQ40Z50 I would prefer to keep as much as possible the same (SMBus, package, etc.)
Is there a way around the 29 Ah limit with the BQ40Z50 or should I go with current scaling in the BQ40Z80?
Would either of the BQ34Z100, BQ34110 or BQ7830-R1 be a better fit?
Thanks
