BQ24250: enable charging using only BOOSTXL-BATPAKMKII?

Hey kel,

Can you try this same test with a lower battery voltage (i.e. <3.5V) and if you get the same result?

Regards,

Joel H

Hi Joel,

     I have a 2 Lithium Polymer Battery 3.7V 1200maH. One is fully drained and the other is at 55%. I short the CE pin the GND and then connect power. The CHARGE ACTIVE briefly turns on and then off.

     I am beginning to suspect that my BOOSTXL-BATPAKMKII is broken. I bought a new Lithium Polymer Battery Battery. Using the Example Program it shows the State of Charge at 70%. I left it to charge overnight for 7 hours. I only place the GND jumper at MPS-EXP432P401R. The CHARGE ACTIVE led is constantly on during that time. After 7 hours the State of Charge is 55%. So the Lithium Polymer Battery is draining instead of charging. Also, I set the BOOSTXL-BATPAKMKII S1 switch to disconnect and I read 1v at 3.3v pin of MSP-EXP432P401R which is unusual. Is my BOOSTXL-BATPACKMKII broken?

-kel

Hey kel,

Is the response the same between the fully drained battery and the 55% SoC battery?

What is the voltage of the fully drained battery?

Also, is the performance the same with and without the MSP430 launchpad?

When you set S1 on the BOOSTXL-BATPAKMKII to 'Connect', what voltage do you see at the 3.3V pin?


Regards,
Joel H

Joel Hernandez II said:

Is the response the same between the fully drained battery and the 55% SoC battery?

Yes.

Joel Hernandez II said:

What is the voltage of the fully drained battery?

20 mV measured from the connector see below pic. This is the Lithium Polymer Battery that came when I bought the BOOSTXL-BATPAKMKII. The battery is not bloated. Several times I charge this for an entire day and it does not charge. That is why I bought a new Lithium Polymer Battery. But when I left it to charge overnight, it drained instead of charging.

Joel Hernandez II said:

Also, is the performance the same with and without the MSP430 launchpad?

Yes.

Joel Hernandez II said:

When you set S1 on the BOOSTXL-BATPAKMKII to 'Connect', what voltage do you see at the 3.3V pin?

20 mV Fully Drained Lithium Battery - 0.29 V measured at MSP430 Launchpad

3.86 V 55% Charged Lithium Battery - 3.3 V measured at MSP430 Launchpad.

-kel

Hi Joel,

     I connect the BOOSTXL-BATPAKMII to power supply and see the CHARGE ACTIVE led on constantly. At the same time connect the MSP-EXP432P401R to the Laptop to see the Battery Data. See, below setup. At Tera Term, I observe the Voltage dropping and also Average Current to be -18mA. If it is charging the Average Current should show positive current value. Does this mean that the BOOSTXL-BATPAKMII is broken? I only used my BOOSTXL-BATPAKMKII a few times and I do not see anything burnt on the board.

-kel

Hey kel,

You mentioned:
20 mV Fully Drained Lithium Battery - 0.29 V measured at MSP430 Launchpad
3.86 V 55% Charged Lithium Battery - 3.3 V measured at MSP430 Launchpad.

Are each of these results with the USB charge connector attached? This is the USB connector on the Booster Pack.


Regards,
Joel H

Joel Hernandez II said:

Are each of these results with the USB charge connector attached? This is the USB connector on the Booster Pack.

No, USB charge connector attached.

The above setup is same with Peter Oakes review below. At his setup it is charging. At my same setup it is discharging. I would like to know if my BOOSTXL-BATPAKMKII is broken so I can buy a new one. I have only used this BOOSTXL-BATPAKMKII a few times and I do not see anything damaged.. 

I am also suspecting that the MSP432 example program is wrong, but I am not an expert with that.

-kel

Hey kel,

Can you try removing the MSP432 launchpad, and powering the Booster pack alone without the battery connected.

When you do that, can you measure the voltage between GND and the switch S1 middle pin (flipped to 'Connect').

Doing this with an oscilloscope is preferred to see the waveform, or a DMM should work to.

Let's investigate the cause of the 'noncharge' behavior before determining it is broken.


Regards,
Joel H

Hi Joel,

I only have a DMM. I observe the CHARGE ACTIVE led turn on briefly after I connect the Booster Pack only to Power. I measure initially at S1 middle pin 25 mV. Then I observe the voltage going down gradually to 21 mV and still going down.

-kel

Hi Markel,

If you refer to the BP's User's Guide and read section 3.1.3, you will learn that the MSP432's example code clears the gas gauge's BIE (Battery Insert Enable) bit. If this bit is cleared, the gas gauge will not be able to detect the battery and report false data to the MSP432. You could either modify the code so that this bit is configured correctly or simply place a jumper on J6 to simulate a battery connect. By doing this, you should see the correct data on the UART terminal. 

Hope this helps!
Seong

Hi Seong Kim,

I commented that code at the MSP432 example program and put a jumper at J6 of BOOSTXL-BATPAKMKII, same result.

From Peter Oakes review above it seems that he made a Energia Sketch program to test out the BOOSTXL-BATPAKMKII. If possible I would like to know if at TI side you are getting the same result from my test result or not. If same then there is a problem with the example program.

If I buy a new BOOSTXL-BATPAKMKII and then it is also discharging, that is really bad.

-kel

Seong Kim said:

simply place a jumper on J6 to simulate a battery connect

I tried this and it is still discharging. I did not modify the example program. The BOOSTXL-BATPAKMKII is connected to Power and CHARGE ACTIVE led is constantly on. AT MSP-EXP432P401R LP the only jumpers remaining are GND, RX, TX.

-kel

Kel,

You mentioned in one of your previous posts that you measured 1V at the 3.3V pin when S1 was switched to disconnect.You will measure some voltage here after switching to disconnect as there are capacitors at the output of the Buck-Boost regulator. If you keep measuring this node, you will see the caps discharge.

When you are charging your battery, is S1 switched to Connect?

Also, you do not need to short the CE pin of the BQ242450 to GND. There is already a resistor, R29, that is pulling this pin low, so you can undo the modification you made here.

Starting with everything turned off, no jumper on J6, and the MSP432 flashed with the default example code, when I switch S1 to connect and reset my MSP432 LP, the image below is what I see on UART terminal.

The state of charge shows 0%. The gas gauge is reporting inaccurate data, because it is not detecting that a battery is connected. By placing a jumper on J6, the gas gauge detects the battery and the next image is what I immediately see on my terminal

Here you see that it correctly displays the remaining capacity and state of charge. Then if I plug a USB into the charge input, the following is what I see

The average current is now positive, and the status shows that the battery is being charged. After a few seconds, I can see the voltage and remaining capacity increasing.

I was able to reproduce the same results with another BATPAKMKII BoosterPack. If you are not able see the same results after following each step, your board may be defected. 

BR,

Seong

Hi Seong,

     Thanks for your time and detailed procedure. Following your procedure I see it charging and see the same result as yours. So, my BOOSTXL-BATPAKMKII is not defective at all. Now, I will follow your procedure to charge my Lithium Polymer Batteries.

      But following my procedure before below, I see at Tera Term output "discharging". So there is some problem there.

      1. Program MSP-EXP432P401R with unmodified example program.

      2. Connect BOOSTXL-BATPAKMKII with Lithium Polymer Battery to MSP-EXP432P401R.

      3. Switch BOOSTXL-BATPAKMKII S1 to connect.

      4. Connect USB Power Charging Cable to BOOSTXL-BATPAKMKII. CHARGE ACTIVE led on constantly observed.

      5. Connect USB Cable from MSP-EXP432P401R to Laptop PC. Open Tera Term. 

-kel

Hi Seong,

I think I will buy a new BOOSTXL-BATPAKMKII to see if I get the same test result.

-kel

Cool, let me know how it goes :)

Hi Seong,

For my initial question, Is it possible to charge the Lithium Polymer Battery without connecting to MSP-EXP432P401R with running example program.

-kel

Yes, ensure that S1 is flipped to 'Connect' when charging.

BR,

Seong

Hi Seong,

Are you using BOOSTXL-BATPAKMKII Rev 1.0?

-kel

Seong Kim said:

Yes, ensure that S1 is flipped to 'Connect' when charging.

Then my BOOSTXL-BATPAKMKII is really broken, since the CHARGE ACTIVE led turn on very briefly and then turns off.

-kel

Hi Seong Kim,

I have concluded that my BOOSTXL-BATPAKMKII rarely works properly.

The steps you gave that says charging at Tera Term, from my test the charging happens only about 2 out of 10 tries. So, it is not reliable if I want to use it to regularly monitor the battery.

With your procedure just now it seems that the Lithium Polymer Battery is charging with just the BOOSTXL-BATPAKMKII. I see that the CHARGE ACTIVE led constantly on. However it does not happen always. I have to try and try until I see the CHARGE ACTIVE led constantly on.

Anyway, I do not know if I am the only one experiencing this using the BOOSTXL-BATPAKMKII. So far I see in the internet only Peter Oakes using the BOOSTXL-BATPAKMKII, but only during his review. At the moment I am not eager to purchase a new BOOSTXL-BATPAKMKII to replace my current one.

I suggest at TI side to do a full regression testing of several BOOSTXL-BATPAKMKII to determine if there is a design flaw.

-kel

Hey Markel,

Just as an FYI, the example was written so that a BAT_INSERT subcommand is issued to the gas gauge after initialization, eliminating the need for any hardware adjustments to the board (J6 header) for the gauge to detect a battery. We have found that this line of code does not properly execute and it has been corrected. An updated software example will be included in the next SDK.

Again, I'm sorry that you received a defected board. If you ever do get a replacement, you should be able to use it with more ease, especially with the updated example.

BR,

Seong