Bangle.js 2 battery stuck at zero?

[espruino-discuss2]

Posted at 2021-12-07 by user137247

I recently received two bangles and noticed that one does not properly display the battery percentage. Is there a way to troubleshoot this?

[gfwilliams]

Posted at 2021-12-07 by @gfwilliams

You could try connecting with the Web IDE and typing E.getBattery() - also I believe analogRead(D3) gives you the raw value - usually 0.3ish

Does the battery still seem to last a long time? It's just that you can't see the percentage?

[espruino-discuss2]

Posted at 2021-12-07 by user137247

Although I can't see the percentage, the bangle has been on for several days without dying- I'd guess this is just an issue with the reported battery percentage.

E.getBattery() returns 0. It looks like D3 is returning a value much lower than expected. I polled it a number of times and observed that the value reported is out of the anticipated range. I'll check back after some time to see if this number is moving at all.

Logs below:

Connected to Web Bluetooth, Bangle.js 5b8f
>E.getBattery()
=0
>analogRead(D3)
=-0.0029296875
>analogRead(D3)
=-0.001953125
>analogRead(D3)
=-0.00317382812
>analogRead(D3)
=-0.00146484375
>analogRead(D3)
=-0.00415039062
>analogRead(D3)
=-0.00219726562
>analogRead(D3)
=-0.001953125
>analogRead(D3)
=-0.00366210937
>analogRead(D3)
=-0.001953125
>analogRead(D3)
=-0.00366210937
>analogRead(D3)
=-0.00366210937

[gfwilliams]

Posted at 2021-12-08 by @gfwilliams

Ok, thanks - so this looks like a hardware issue then - I doubt there is anything that stops the watch being useful, but it seems that there may not be a connection from the battery to the pin D3 that measures the voltage :(

On nRF52 the small negative values are usually what happens when the pin is connected to GND outside the microcontroller.

Not quire sure what you want to do - we're very low on watches so would have to send out a replacement in the new year, or I could give you a discount?