• Hi everyone,
    I got my bangle.js from the original Kickstarter campaign a couple of years ago (and even wrote an app for it). I've not used it for quite a while and now it seems, that the battery is dead: even when I charge for some time (>1h) the watch does not react on any of the buttons.

    I found the video on opening the device (https://www.youtube.com/watch?v=GJHC925y­ti0
    ) and the type of the battery (3.7 V 280 mAh 502527) which was mentioned in the video description.

    Unfortunately, the video does not show, how to replace the battery, so the question is: does anyone have replaced the battery already and could give some hints, how to do this?

    Kind regards,

  • This is strange, even with dead battery the device should work when on charger. If battery is dead it typically dies quickly when you take it off the charger. Did not try with Bangle 1 but that's how it works with other devices. It powers on even with battery completely removed when you attach charger. Are you sure it is actually charging? It can be bad cable or attached in wrong way.

  • I can measure ~ 5V at the pins of the cable, when attached to a USB charger, so I do not think that it is a bad cable.
    I'm quite sure, that I've attached it in the correct orientation: if the watch lays face down, the cable comes from the left side, if the watch is face up, the cable comes from the right. But there is also no indication of ongoing charging (I can't remember, if there should be some indication).

  • Did you definitely try holding BTN1 down (top right) for a few seconds? The Bangle won't turn on as soon as the button is pressed - it's to stop it coming on in transit.

    We did have an issue with Bangle.js 2 where sometimes charging wouldn't start if the battery had been totally flattened - and you could sometimes sort it by just making sure the Bangle was warm when you started charging - so you could try that.

    But if you really need to replace the battery, what you have to do is when you have the 'puck' out from inside the watch case, you carefully fold back the flex PCB with the buttons on it - then you can 'unwrap' it from around the back.

    At that point you could pull the battery out from the back, cut the wires, and solder wire-to-wire.

    Or, the better option is to remove the LCD+PCB assembly from the plastic frame, and then you can get to the PCB to unsolder the wires.

    Sometimes you can even just 'jump-start' LiPo batteries though - if you put 4v or under on the LiPo contacts, it can reset the protection circuitry and bring them back to life.

    ... but I'd try less drastic measures first!

  • And BTW it sounds stupid but did you try to attach cable both ways? The one I have fits both ways = magnets attract in both ways but only one way works of course.

  • Thank you all for your answers. I tried a different charger today and after some hours, my watch came to life again :-)

    So it really seems, that there is no need to exchange the battery for now.

  • Hi Gordon, I tried a different charger today and charged for some hours again. Finally the watch started working again. Thank you for your great work and support.

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How to replace the Battery on the original Bangle.js?

Posted by Avatar for eska-muc @eska-muc