Battery life only lasting one or two days?

[espruino-discuss2]

Posted at 2022-08-07 by user147874

Hi,

I recently bought a bangle js 2, and after installing the Poketch watch face and the blackjack game (and wearing it, checking time maybe every half hour?), the battery life seems pretty low. I only get about a days worth of use before it drops to 10-15% from full.

Is there a setting I'm missing to improve this? The screen brightness is lowered and I turned off the wake on twist so it's just the button but it still drains really quickly.

Has anyone else experienced this?

[espruino-discuss2]

Posted at 2022-08-07 by johan_m_o

Normally you should be able to go about a week without charging, unless you run the GPS all the time or have something else keeping the watch awake.

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Posted at 2022-08-07 by sorrel

I have a suspicion that the Poketch clockface could be causing that – it looks like it redraws itself once per second whenever the display is on, which on Bangle 2 is "always": https://github.com/espruino/BangleApps/blob/387e037a6111af84ff3625f2c7091376a5582d91/apps/pokeclk/app.js#L75

The lock event is potentially more useful on Bangle 2, but really once-per-second updates are overkill; there's a neat trick you can do to schedule once-per-minute updates for immediately after the minute ticks over, which mtnclock uses: https://github.com/espruino/BangleApps/blob/387e037a6111af84ff3625f2c7091376a5582d91/apps/mtnclock/app.js#L345

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Posted at 2022-08-07 by johan_m_o

Considering it doesn't look like that watch face even uses seconds it seems weird to redraw it that often... That would do it though.

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Posted at 2022-08-09 by @gfwilliams

I'd definitely give it a try with a different watch face (maybe just the default Anton one) and see what happens.

Generally the clock face (and some widgets) can have a huge impact on battery usage. It's just one of those things - Bangle.js provides a lot of flexibility but that can also mean a lot of ways to drain the battery faster, especially as it's just not possible for me to manually test every clock face.