How to Test if Laptop is Charging The Battery

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  • Zentech
    Senior Member
    • Feb 2021
    • 94
    • Usa

    #1

    How to Test if Laptop is Charging The Battery

    guys, I have a laptop hp chromebook 14 and the operating system was not recognizing the battery. I opened and tested the battery connector to the motherboard for output. I found like three different voltages must of them 3.3V. Then I looked online for voltage of motherboard to battery in HP laptops and found the pinout of the connector. Needless to say I was surprise to see that the laptop doesn't charge the battery with 12v. I tested with the meter and it was like 3.3V in three different pins and two of them were ground. Then I search for articles on how to test battery and found this
    http://kuzyatech.com/testing-laptop-...harge-capacity

    my question is how can you really be sure the laptop is properly charging the battery and the problem is the battery and not the motherboard. what are the voltages on that connector. The curious thing is that when you unplug the charger the laptop provides 12V back to MB. How is that if it charges only with 3V.

    Thanks to all in advance
  • mon2
    Badcaps Legend
    • Dec 2019
    • 14169
    • Canada

    #2
    Re: How to Test if Laptop is Charging The Battery

    Hi. Hope it is warmer there than here.

    1) Post any silk screen markings on your logic board. Perhaps, with some luck, we can find a schematic.

    2) Review the battery connector and surrounding parts. If possible, take clear and zoomed up pics of the area. You should find a square charger IC with perhaps the markings of 'BQ' = Texas Instruments. They apparently sold billions of these charger ICs to the industry. Once we know for sure which one is onboard, we can study reference schematics to review your logic board.

    3) At this time, suspecting that your logic board is NOT charging the battery due to the low charging voltage but could be wrong. The 3v3 you are reading are the SMBUS interface pins (SCL / SDA) that are used by the host SMBUS master to extract stats out of the BMS (battery management system) which is inside the battery pack under test.

    4) Once you remove the adapter, the voltage that is left on your battery is used to power the board = ~12 volts.

    Q1: What is the adapter voltage for this laptop? Is it ~19 volts ?

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