bq78pl116 design capacity

You can change the Design Capacity parameter on the Charge Control tab in bqWizard.

I know. But if I set the Design Capacity to a specified value I can only calculate the Absolute State of Charge precisely only when the cell has the Design capacity. When the cell ages the capacity will be lower than the Design Capacity so I shouldn't use the Design capacity to compute the Absolute State of Charge. 

"Design Capacity is a parameter in the data set. It is not changed by the gas-gauging algorithms, but is used in the determination of Absolute State of Charge"

Gaetano

The device was designed to keep the Design Capacity fixed and use the ASOC value to provide a figure of merit as to how the pack is aging. It uses RSOC to provide gauging from run-to-run. FCC is updated as the pack ages and this will allow RSOC to reach 100% on each cycle.

Regards
Tom

Thanks. This is a very useful feature!!! But it works well though the battery cells are new? I found some problems assessing parameters in the 80–100 percent operating range of the battery life.

Another two questions :-D

1) At page 81 of the Technical Reference Manual compute RSOC as the ratio of remaining capacity (0x0F) and remaining capacity (0x10). Is this an error right? It should be the ratio of Remaining Capacity and Full Charge Capacity. 

2) At the same page it is calculated the Update Run Time to Full. What does it means that is Not Supported? 

Thanks.

That is a typo in the equation. Address 0x10 is the FullChargeCapacity. It should not read RemainingCapacity. I did not see the reference that the Update Run Time to Full is not supported on page 81.

Yes sorry. It is page 53 that talk about RunTimeToFull (0x05). 

"5.1.3  AtRateTimeToFull(0x05)
This command is not supported " 

Gaetano

I checked with the firmware team and these features were never implemented in the firmware. They are not going to be available for use.

Regards

Tom

Hi Tom,

thanks for your support. I would like also to know what are these parameters and how are they calculated from bq78pl116 : 

1) Charge Inhibit Temperature Low

2) Charge Inhibit Recovery Temperature Low

3) Charge Inhibit Temperature High

4) Charge Inhibit Recovery Temperature High

5) Pre-Charge Temperature

6) Charge Suspend Temperature Low

7) Charge Suspend Recovery Temperature Low

8) Charge Suspend Temperature High

9) Charge Suspend Recovery Temperature High

10 ) Discharge Under Temperature

11) Discharge Under Temperature Recovery

12) COV High Temperature Adjust

13) OT Charge Threshold  (is it possible to know the max and min temperature during charge and discharge ?) 

14) OT Charge Recovery

15) OT Discharge Threshold

16) OT Discharge Recovery

17) Discharge Under Temperature

18) Discharge Under Temperature Recovery

19) COV Threshold (Is it possible to know if a single cell go Over Voltage or Under Voltage) 

20) CUV Threshold

I know that are a lot of questions.... If you have a more detailed explanation of these parameters please send it to me. 

Thanks.

Regards

Gaetano,

The TRM provides the best descriptions of these parameters. They are set by the user to tailor the pack to the required operating profile. Please let me know if you have a specific question.

Regards
Tom

Yes. My question are : 

1) Is it possible to know what are the maximum and minimum temperature under charge and discharge? 

2) Is it possible to register the events  "single cell goes Over Voltage" and  "single cell goes Under Voltage" ?

Thanks for the support

Gaetano,

1) Are you asking what the max and min temperatures allowed during charge or discharge? Or, are you asking about what was the max or min temperature that occurred?

2) The CUV and COV faults are at the cell level, but they do not distinguish which cell was at fault.

Regards
Tom

Hi Tom,

1) I would like to know if is possible to know what are the min and max temperature that occurred during charge and discharge.

2) So there aren't parameters that let me know which cell goes under or over voltage.

Regards.

Gaetano