TPS25751: TPS25751D+BQ25713: Unexpected discharging current issue from mounted battery pack

Hi Kim, 

Several follow-up questions to help clarify the issue: 

1. Can you provide the JSON files for v006 and v007?

2. Are you able to capture any PD logs for both v006 and v007 config? 

3. Can you provide block diagram of your full system? 

4. What kind of PD adaptor are you testing with and what are its PDO capabilities? 

5. Is the description below for v006? 

Kim Jae Kwang said:

To solve this issue, changed PDO3 to 15V/3A and PDP to 45 watt. Auto Negotiate max current(0x37) is still 3A. 

Then, power test is "PASS" and the battery is not fully discharged, normal working.

(it is called "PD-firmware-version-V007)

6. Can you elaborate what did you mean by the battery is completely discharged? Is this the battery connected to the DUT with BQ25713 or is there a battery on the 30W PD adaptor side? 

Kim Jae Kwang said:

Even though the external 30watt PD adapter is sufficiently capability to supply the required current of the DUT, it is happened that the battery discharged unnecessary current according to the PDO and PDP configured value in the PD protocol. As a result, the battery is completely discharged and the DUT is automatically turned off.

Thanks and Regards,

Raymond Lin

Dear Raymond,

Thanks for your join on this thread.

1. V006 &V007 Json files: pls refer to the attached
2. Log file on the issue: Unfortunately, it can not be available now
3. DUT block diagram: pls refer to the attached
4. USB Type-C PD adapter        : it can supply power up to 30W, and detailed support power is as  below15V/3AJSON(V006&V007).rar

            1) 5V/3A

            2) 9V/3A

            3) 12V/2.5A

             4)15V/2A

        5. Yes, you’re correct, and it was a typo. It should be V006 with 15V/3A and PDP to 45 watt

        6. It is mounted to the DUT inside with BQ25713, and “completely discharged”, which means there is no remaining capacity.

            To add more explanation, when plugging the DC power from the external PD adapter to the DUT, the expected BAT working condition is like this

             1) DC power(external PD adapter) connected

             : BAT can start to charge, and if the operating current required by the DUT is greater than the current supplied by the external PD adapter

               ,the BAT can be discharged to replenish the current simultaneously.

                This is a normal operating state.

 However, the problem is that in DC mode(external PD adapter), the PD firmware (V007) causes the discharging current to be greater than the charging current of the battery, and as this condition lasts for a long time (around 23 hours), the battery capacity changes to the low battery state and eventually the DUT is shut down.

With V006, it is not happened same problem as the above.

So, this is why it is necessary to have TI's support and to know the root cause

.Teufel OA2502_BLOCK.pdf

Raymond is out of office this week. He will be back next week and respond on this.

Hi Kim, 

1. How much power is required by your system that is causing the DUT to lose power with v007? Does it require more than 30W (15V/2A) that the PD adaptor can provide? 

2. Can you collect I2C logs between TPS25751 and BQ25713 with both configs during the 15V contract with the PD adaptor? I would like to see if there are any major differences in the I2C log between the two configs.

3. Do you see this behavior with other PD adaptors with similar power ratings? 

Thanks and Regards,

Raymond Lin

Hi, Raymond,

Q1-answer> 

Pls find "Max Output Power Draw from 30W PD Adapter" table in the previous one.

Briefly, the external 30W PD adapter can supply the same power to the DUT regardless of V006 or V007 within a short time. But, the only problem is that it occurred during a long-term test, as much as around 23H. (Power test required total playback times are 100H)

Q2-answer> I would arrange this test to get the required log file as soon as possible. Then it'll be provided for you.

Q3-answer> No. Unfortunately, we haven't tested it with another PD adapter.

Hi Kim, 

Regarding Q1, can you elaborate exactly how much power is required by the DUT in order for the system to be powered on outside of charging the battery? Does the rest of the DUT system consume too much power that the battery can't charge simultaneously?

Regarding Q3, it'll be beneficial to see if this behavior happens with other chargers with similar power capability (~30W) or lesser power as well. 

Thanks and Regards,
Raymond Lin

Dear Raymond,

Sorry to wait for you. We're working to get the log file with the failed case from the power test.

The test was done last night. But, unfortunately, the unit was working well, and the result was "PASS".

So, Failed to get the log file from the DUT.

I will make the test again with the previously failed unit and try to get the log file.

Then, let you know the result.

Thanks for your patience. 

Best regards,  

JK.Kim

Hi Kim, 

Thank you for the update, we'll be waiting for the test results. 

Thanks and Regards,

Raymond Lin

Hello, Raymond,

I appreciated your patience. Among the 2 power tests, it took a long time to get the log file with the failed status because the problem did not occur. Please see the attached file with the failed condition and check it.

Best regards,

JK.KIMOA2502_log_20250529.txt

Hi Kim, 

I'm unable to open the log due to the file size. Reviewing our previous conversation, this seems more of a efficiency issue with the battery power management. I'm forwarding this thread to the BQ team for their input. 

Thanks and Regards,

Raymond Lin

I did not see anywhere mention efficiency. Please submit a separate thread for the BQ questions. 

Dear Raymond &Tiger,

I attached a simple summary file containing the failed log record.

Briefly, we did the power testing for 140 hours and recognized that this issue could be duplicated even though the battery capacity is not fully discharged.

The main problem is that there is no output power from the PD IC (TPS25751) once this issue occurs.

Pls help to check the attached Excel file.

Best regards,

JK.Kim

Power test (Failed)-Log-PD V007.xlsx

Hi Kim, 

When you said there's no output power from TPS25751, are you referring to voltage on the PD PPHV pin? 

Since the issue seems to occur after long duration of charging, it does not seem like root cause is entirely on the PD unless you observe PD (TPS25751) is disabling its PPHV pin abnormally.

Another possibility is when the PD+BQ system negotiates a 15V/2A contract (in comparison to 15V/3A), the PD (TPS25751) will configure the BQ25713 IIN_DPM based on the negotiated contract.  Are you able to capture PD logs with a PD analyzer when connected to the wall adapter so we can see if capability mismatch is being set? If you don't have a PD analyzer I recommend using the TI-PD-Analyzer tool to capture logs: https://www.ti.com/tool/TI-PD-ANALYZER 

Thanks and Regards,

Raymond Lin