My Bangle JS2 battery has gone 37 days and is at 9% now #6500
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Posted at 2023-10-26 by @gfwilliams That's great to hear! I usually only hear complaints when something is going wrong. Over a month is what I routinely see here too with the watches I have kicking around. When there is movement the accelerometer does enter a higher power mode and that can affect battery, but it's not massive. The backlight is a massive power draw if 'wake on twist' is enabled too. Posted at 2023-10-26 by ccchan will apps like "pattern launcher" and "seconds" in the clock face (I use anton clock plus for seconds) heavily reduce the usage time? btw, the temperature is almos always 30-31oC even the temperature in my town range from 25-32, how can i test it? thanks Attachments: Posted at 2023-10-26 by @thyttan Here @fanoush has taken the time to explain power draws from updating the screen: https://forum.espruino.com/conversations/390481/#comment17137544 :) Posted at 2023-10-26 by ccchan so, u guys with seconds off, update screen only 60x24, Posted at 2023-10-26 by @thyttan Yes, more or less 👍 Posted at 2023-10-27 by @gfwilliams Yes - showing seconds really hurts battery usage. Some clocks are better than others though - if they update just the seconds text every second then they'll waste a lot more power than one which redraws the whole screen every second. Posted at 2023-10-27 by @thyttan
Good to know, thanks for the insight! I would have thought it was the other way around. Posted at 2023-10-27 by @fanoush typo? lot less power if you update just the second text? Any nontrivial piece of javascript takes tens or even hundreds of miliseconds to execute. Posted at 2023-10-27 by @gfwilliams Sorry - maybe I wasn't clear - what I mean is, in order of power usage:
Updating every second will still hurt battery over updating minutes, but it's significantly better than the whole screen. I know some watch screens can take almost a second to update, so in that case the CPU is occupied pretty much all the time. But for example this code, tried just now, takes around 3.5ms, so isn't going to be so painful at all:
By contrast Anton Clock plus redraws everything and when seconds rendering is enabled it takes around 175ms every second, so obviously is going to be terrible! Posted at 2023-10-27 by @thyttan Ah, ok. That makes more sense 😉 Thanks! Posted at 2023-11-01 by Fteacher Reading this topic, I was thinking about the run+ app. Posted at 2023-11-01 by @thyttan IIRC I made the graphics for the hr intensity screen to draw pretty lazily. But maybe it could be taken further! Posted at 2023-11-01 by HughB By far the biggest power draw is the gps. Screen updates are less taxing. Be sure to have wake on twist setting set off otherwise your backlite will come on all the time you are moving about. The gps will discharge the battery from 100%-0% in about 6 hours. The battery life of the run app could be extended much further by turning the gps on until it gets a fix, off for 30 seconds then on until it gets a fix. I did this in the gpsclock info and was able to use the gps for 48 hours. When moving about the time to get a fresh gps fix from power on will increase and may take a while longer. Posted at 2023-11-02 by @gfwilliams As I understand it the Run+ app is basically the Run app with an extra screen, and the Run app uses Layout which should update lazily. In fact there was an issue a few weeks ago where the Lazy draw was meaning the screen didn't update correctly after a prompt was shown so I think we're good. But exactly as @hughb says: The LCD backlight is the biggest power draw in the system so if it comes on by accident when you run, that will really hurt battery life. And GPS is second largest power draw - I guess it might be possible to implement something in the You should also make sure you use the AGPS app and set up just It should be possible to configure the GPS itself into a low power state, but the documentation for the chip really isn't great and unfortunately I haven't been able to find out anything useful Posted at 2023-11-02 by HughB
There was quite a bit of experimentation done a while back by @Mark_M (I think or Mark someone). I would post the thread but I never been that successful with the search tool in the forum. One of the findings was that certain documentated features did not seem to respond and appear to be working. I have never had time to go back to it to look. @FTeacher - might be worth testing your watch out on a window ledge where the GPS will get a fix. Download the AGPS data, switch on the run app and get a fix. Then leave it for 4 hours and check what the battery level is. Then repeat and add in the bluetooth heart monitor. Posted at 2023-11-02 by tev I estimate that I'm typically getting up to around 2 weeks regularly wearing the watch with:
which seems pretty reasonable. In practice since I use the watch as a daily driver I normally charge a bit more often than that to avoid the battery dying at a bad moment. Since the battery meter tends to hang out around 9–10% for a long time it's hard to be sure what the true max runtime would be without risking that; I consider that level as a sort of “charge as soon as possible” low-battery signal. I do notice that long use of timers that update in 0.1-second intervals tend to drain the battery particularly rapidly. (At least one app seems to do such updates only when the screen is awake/unlocked and then cuts back to once per second, which seems like a good idea.) But occasional use of once-per-second displays for a few hours here and there doesn't seem to hurt overall runtime too badly. Posted at 2023-11-03 by Fteacher Thanks for your help ! Obviously the culprit was the wake-on-twist. It is very handy while running, but the power draw being so high, it can be advantageously replaced by wake-on-tap. I did a short test run today and I realised 1)I don't need any backlight if running in daytime. 2) Just this might be enough to save enough energy to handle 2h30 in a row. I'll test that next week with a long run. Posted at 2023-11-03 by HughB
I doubt it will make any difference as the gps will still be fully powered between fixes. But the proof is always to test and compare. Posted at 2023-11-21 by Fteacher I saw there's been updates in Run+ and recorder not so long ago, was something changed ? I went for a 1h25 minutes run with batteries fully charged. I had AGPS with gps+glonass, the BTHRM and using the run+ app. Back at home, I checked the battery after a shower, and it showed 71% left ! Still, during the run itself, the battery gauge, visible in the run+ app, went down to 1/3. Is that something I should be worried about ? I have an almost 3 hours race coming this weekend... Posted at 2023-11-22 by @gfwilliams Nothing has changed apart from a minor bugfix - when a dialog popped up the screen wasn't cleared, that's it. If you need the best power consumption do turn off Glonass - I can't remember exact figures but IIRC it uses about 70% of the power if you just go for GPS Posted at 2023-11-22 by HughB 71% after 1.5hrs with GPS sounds about right to me based on my experience. I have noticed when there is a lot of stuff drawing power that the % pwr will recover a bit after you switch the power drains off. Hope that helps. |
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Posted at 2023-10-25 by HughB
Pleased to report that I have got 37 days of continuous use of a Bangle 2 from a single charge.
18 sep 100%
21 oct 19%
25 oct 9%
I decided to end the test today and put it on charge as I have not been checking it that often.
The watch was left in a draw for that time. I think if it had been on my wrist, using the step counter, back light and it would not has lasted so long.
My configuration for the test was the Lato clock, all the clock_info's , with the sunset one selected.
I normally get about 2 weeks from my general use now. I quickly consume the battery if I flash apps multiple times.
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