12 Replies Latest reply on May 16, 2017 11:40 AM by Intel Corporation

    Battery not charging

    eab

      I am having power problems on my Joule.

       

      It powers fine from a wall supply, but when I provide power on the barrel plug from a battery through a 12V DC/DC regulator, it does not boot. After lots of debugging and searching, I have determined that even though my DC/DC regulator is rated at a much higher current than needed (something like 5A at 12V), it is not able to supply the current quickly enough on boot. The Joule goes from no power to lots of power too quickly for the regulator.

       

      My solution was to use the supplemental battery. There are pins to add a 1-cell Lithium battery that mux's with the barrel supply to add extra power for boot. This all works great, initially. According to the documentation, the 1-cell battery is supposed to get charged when it is not being used. I can see the charging IC on the expansion board. However, the battery is not charging. The cell was completely depleted after a few days of intermittent use.

       

      Is there some kind of enable that I am missing for the charger? Is there a software parameter to set somewhere? Or a hardware pin to raise high?

        • 1. Re: Battery not charging
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hi Eab,
           
          Thanks for your interest in the Intel® Joule platform.
           
          We would like to know a little bit more information, could you please let us know if you are using the Intel Joule Expansion board breakout? Also, which pins are you using to connect the 1-cell Lithium battery and charge it?
           
          Regards,
          -Yermi A.
           

          • 2. Re: Battery not charging
            eab

            Yes, I am using the Expansion Board.

             

            I am using the pins labeled "battery" that are located immediately adjacent to the barrel plug.

             

            There is a pin on the module itself labeled CHRG_EN_N (Pin 35 on J6 on the module itself). The description says that this pin enables the charging of the battery, and is an output pin.  It also says that it is connected to GPIO_15.

             

            35 CHRG_EN_N Output General purpose input/output for the expansion board charger’s enable pin, active low. Allows battery to be charged when power is connected to +VDC_IN on the expansion board. Connected to GPIO_15.

             

            How do I set this pin? I'm running Ubuntu 16.04.

            • 3. Re: Battery not charging
              Intel Corporation
              This message was posted on behalf of Intel Corporation

              Hi Eab,
               
              Thanks for all the information provided. I was looking at the Intel Joule documentation and currently, the Intel Joule Expansion board breakout is not capable of charging a battery, and you would need an external circuit for that functionality. Please take a look at the Battery Path and the Module Board-to-Board Connector Pinout for more details about that.
               
              Hope this information helps.
               
              Regards,
              -Yermi A.
               

              • 4. Re: Battery not charging
                eab

                Is this something that is planned in future software/kernel updates? The board itself seems to be capable, since the IC chip is a charging chip.  It should just be a matter of enabling charging by sending the proper I2C command and pulling that CHRG_EN pin high.

                 

                In the mean time I will find another solution.

                • 5. Re: Battery not charging
                  Intel Corporation
                  This message was posted on behalf of Intel Corporation

                  Hi Eab,
                   
                  As you have mentioned the EU2 is a charging chip, however, I currently don’t have information about when it will be available, we’d recommend you to keep an eye on our community.
                   
                  Regards,
                  -Yermi A.
                   

                  • 6. Re: Battery not charging
                    DonnieP

                    Yermi,

                     

                    The schematic that I have on the Joule Expansion Board Schematic and the EU2 (BQ25892RTWT) - which is I2C Controlled Single Cell 5-A Fast Charger with MaxChargeTM Technology for High Input Voltage and Adjustable Voltage USB On-the-Go Boost Mode.   Is this something in future?   Am I missing something here?

                     

                    Don

                    • 7. Re: Battery not charging
                      Intel Corporation
                      This message was posted on behalf of Intel Corporation

                      Hi Don,
                       
                      Currently, according to the Joule documentation provided above, all battery solutions must be completely external to the expansion board, the EU2, which is a charger chip as you have mentioned, and at this moment serves as the +VSYS voltage regulator. I’d recommend you to keep checking our community for future updates about that.
                       
                      Regards,
                      -Yermi A.
                       

                      • 8. Re: Battery not charging
                        DonnieP

                        Yermi,

                         

                        Is this because you have pin 4 of EU2 pulled high to indicate charging is disabled?   If we remove this resistor, would this enable charging?      Other than software that would disable the charging, this is all that I can see.   Do you know if the the I2C Software is ready on the Joule for the battery operations?

                         

                        From the datasheet on Pin 4 of BQ25892:

                        Open drain charge status output to indicate various charger operation. Connect to the pull up rail via 10-kΩ resistor. LOW indicates charge in progress. HIGH indicates charge complete or charge disabled. When any fault condition occurs, STAT pin blinks in 1 Hz. The STAT pin function can be disabled when STAT_DIS bit is set.

                        • 9. Re: Battery not charging
                          Intel Corporation
                          This message was posted on behalf of Intel Corporation

                          Hi Don,
                           
                          The Intel Joule Module datasheet states that the pin 35 on the Joule Module is the CHRG_EN_N pin, which is the pin in charge to enable the battery charge (refer to pin 9 in BQ25892RTWT):
                           
                          “General purpose input/output for the expansion board charger’s enable pin, active low.
                          Allows battery to be charged when power is connected to +VDC_IN on the expansion board.
                          Connected to GPIO_15”
                           
                          According to the Module Board-to-Board Connector Pinout, “module J6 Connector interface” section, the pin 35 is no connect, so I believe for this reason it is not enabled to charge a battery. The pin 4 (STAT) of the BQ25892 is an output that indicates various charger operations.
                           
                          Moreover, please let me investigate if it can or cannot be enabled by software and as soon as I have use useful information I’ll let you know.
                           
                          Thanks for your patience.
                           
                          Regards,
                          -Yermi A.
                           

                          • 10. Re: Battery not charging
                            Intel Corporation
                            This message was posted on behalf of Intel Corporation

                            Hi Don,
                             
                            Thanks for your patience. After investigating, I would like to let you know that the battery charger device (EU2) on the Intel Joule Expansion Board was selected to allow powering of the Joule module from either an external power supply or a battery. Unfortunately the Joule BIOS does not support the ability to enable the EU2 device for battery charging. If battery charging is required, we suggest to use an external solution to power the expansion board that uses a battery charging device designed for the battery chemistry, configuration, and capacity of the user target solution.
                             
                            Hope you find this information useful.
                             
                            Regards,
                            -Yermi A.
                             

                            • 11. Re: Battery not charging
                              DonnieP

                              Yermi,

                               

                              Fully understand that the Joule is too new of a product and not all the code/features are completed but is this on the road map and do you have a estimated when it will be addressed?     

                               

                              Thank you,

                               

                              Don

                              • 12. Re: Battery not charging
                                Intel Corporation
                                This message was posted on behalf of Intel Corporation

                                Hi Don,
                                 
                                Thanks for understanding. I would like to let you know that I’m not able to discuss about roadmaps or future plans for any product, however, I’d recommend you to keep an eye on our community for any news.
                                 
                                Our apologies for any inconvenience it may cause.
                                 
                                Regards,
                                -Yermi A.