Battery Life

Hello,

I think there is something wrong with the battery in my device:

• Device: BangleJs2
  
• Firmware: 2v13
  
  

I did factory reset, settings are default, additional apps gadgetbridge, GB debug.

Before factory reset gadget was working 2 days only.
after reset: device was fully charged on 14.05.04 22:00 today 16.05.04 16:14 current battery level 51% is this normal ?

p.s.
Gadgetbridge usage i minimal, default settings always connected notifications are filtered and have received 15 notifications during this period.

How long did you keep it in charge?

Also worth adding - are you using it until the battery level is 0, or until it turns off?

Because it can be in some watches that the battery level indicator isn't calibrated right - but recalibrating it with the 2v13 firmware is pretty straightforward

How long did you keep it in charge?

Based on gadgetbridge it took 2h30m to charge,i stoped charging exactly on 100

Also worth adding - are you using it until the battery level is 0, or
until it turns off?

It turned off on 0

It got to 0 and device switched off today aprox hour ago.

Attaching screen from gadgetbridge

1 Attachment

Ooooo. Looks like the battery plot works in GadgetBridge now.

Please could you leave the Bangle charging overnight and see if that helps? When charging the battery voltage reads higher, so a 100% battery reading doesn't mean it's fully done charging....

Also what kind of battery life do you get with the watch just sitting with no bluetooth connection and not worn? I know the 'LCD Wake on Twist' setting can be overly sensitive for some people, and the LCD backlight draws a bunch of power (it'll flatten the battery in 12 hours) so if it's coming on a lot for you then that'll have a big effect

I have kept it overnight, same issue gadget worked for 3 days and died. LCD Wake does not seem to be an issue at least i have not noticed this happening a lot.

I am currently Re-charging and will try idle with no Bluetooth and post the results.

I understand that 4 weeks is not something that i have to expect, what is average daily battery usage in general scenarios? (Meaning no development just watch and Gadgetbridge for notifications. )

You could definitely expect to get as little as 3 days with certain apps installed and settings tweaked, but if the device really has been reset to just the default apps, plus Gadgetbridge, and no other settings were tweaked then it does seem like there's an issue.

How long have you had the Bangle? Has it always been like this?

Maybe others can chip in here with their experience of Gadgetbridge battery life?

Use the recalibrate feature in settings menu, don't stop at 100, then see if that helps.

@d3nd3-o0 I'm afraid the battery percentage reported won't affect how much the battery can charge, or when it shuts off, so I don't think it'll help in this case

How long have you had the Bangle? Has it always been like this?

I have the device for few weeks and it has been like this from day 1.

I did one more factory reset, this time haven't installed any apps, no connections were done and kept the device idle on the table.

Question is how do i check percentage of battery?

p.s.
Is this the scenario were device should last 4 weeks ?

The easiest to find battery percentage is probably to use the https://banglejs.com/apps/?id=widbatpc widget

I know but than i have to connect my device to pc/mobile which will ruin debuging process.

Even if it remove connection after installing app not a fact that following app is optimized enough to not have impact on final result.

no connections were done and kept the device idle on the table.
Is this the scenario were device should last 4 weeks ?

Yes, it should do. Only thing that'd stop it is if devices kept connecting to Bluetooth (but you could even disable bluetooth in settings)

Question is how do i check percentage of battery?

You still have the battery indicator showing in the top right? It's not an exact percentage, but then the percentage you get reported is only maybe 10% accurate anyway.

Just going to chime in here, I have also had 3 days battery life since day 1, I charge the watch for at least an hour more than when it’s at 100%, normally about 4 hours and then it dies roughly 3 days after the charge.

My watch has been reset a couple times now and the settings are all default, only additional apps I have loaded is the iOS integration, messages and my seiko watch face which I assume the watch face shouldn’t be draining too much battery as it’s using drawImages.

I don’t have heart rate on or gps, I actually had heart rate on every 10 minutes at one point and had the exact same battery life then as I do with it off and I have made sure it isn’t still activating.

I have charged the watch for about 6 hours previously to make sure it was definitely fully charged and found no difference in battery life, 3 days seems to be all I get.

I probably have the watch go off to about 20 to 30 notifications a day

my seiko watch face which I assume the watch face shouldn’t be draining too much battery as it’s using drawImages.

If the clock face updates every second then it'll drain a lot of battery. Do you turn off the watch at night?

Many clock faces update seconds only when screen is unlocked to preserve battery.

I don’t turn the watch off at night no.

I might try updating the watch face to only show seconds when the screen is unlocked and see how that affects my battery life.

I assumed the drain shouldn’t have been too bad with drawImages as that should only be updating the screen with the pixels required, although I’m not 100% on whether that’s specifically the pixels that change or done by segments of the screen getting updated.

I might also have a play with when the screen unlocks on the watch as I find sometimes it triggers when I don’t want it to then when I want it to it doesn’t trigger

I think waking up in itself is expensive, regardless of what is actually done after. So refreshes every second are 60 times as expensive as doing that only every minute, in regard to the cost of waking the processor from sleep. Drawing to the screen is relatively slow and I suspect it keeps the processor awake that whole time.
drawImages documentation says it should render "only" the rectangle that is needed to cover the images, but that seems to be all pixels of every used image so it will probably only save relevant amounts of time if the images are small. Updating only changed pixels would need some way of a fast check for change between what will be drawn and what is on screen. I do not think that exists in a way that is faster than just rendering all pixels.

Do you turn off the watch at night?

Please don't do this! As long as the clock face just updates every minute, having it on over night shouldn't be a big deal.

But yes, updating once a second can be a big draw. If you're just updating the seconds digits on a digital clock it won't be too bad but very few clock faces do this - they usually redraw everything

drawImages will do just the bounding rect, but if you've specified a background image, then the bounding rect is going to be the entire area of that background image so that won't help you. There are some analog clock apps that are a bit smarter about the area they update, but even so it will hurt battery updating every second.

Is yours this app? https://banglejs.com/apps/?id=seiko-5actus

Because it seems you clear the screen (twice), and then redraw everything (including all widgets) once a second: https://github.com/espruino/BangleApps/blob/master/apps/seiko-5actus/app.js#L162-L165

So actually I'd say 3 days life is probably not a huge surprise from that...

You could use some code like this though, and ensure you redraw just the area around the second hand (and where it was) and it would probably have a pretty drastic effect: https://github.com/espruino/BangleApps/blob/master/apps/analogimgclk/app.js#L41-L95

That is correct and I see now where I’ve gone wrong, my intention was to draw the background once and then not have it redraw and only redraw the hands, not sure why I put it in the display refresh loop, was a bit silly of me. I’ll have to update that code to not redraw everything like that and see what happens, but I’d agree that my watch face is most definitely my issue of only getting 3 days battery life.
Also not sure why I’m making it redraw twice, I typically don’t get a chance for hobbies until after I’ve put my son to bed, so I’m just going to blame it on end of day brain fog haha.

That analogimgclk has some nice code in it, I’ll have to have a proper look at how it’s handling the images and implement something similar into mine.

I’ll have to find some time this week to sit down and rewrite a chunk of that code as there’s a few things I can see I want to change and optimise in it

Great, thanks! At the end of the day it doesn't really matter though if it works for you.

But for anyone with battery life issues, check what apps you have installed first! Bangle.js is intentionally very flexible and open but that does mean that apps can have a huge effect on your experience of the device as a whole.

I think waking up in itself is expensive, regardless of what is actually done after.

Not really. The CPU needs to wake up all the time to keep Bluetooth protocol happy so waking/sleeping is fast and is not an issue. nrf52 can last months from coin battery sending advertising packets every few hundred of milliseconds which wakes up CPU and radio for every packet.

So it definitely depends on what is actually done after waking and for how long. The power is drawn by CPU being busy running code or by some other hardware which is not put to sleep . Bangle running any JS code from flash storage makes CPU and SPI flash chip busy. Drawing to display keeps CPU and display busy.

Bangle running any JS code from flash storage makes CPU and SPI flash chip busy.

So would it make sense to load redrawing code into "ram"? (especially thinking about clocks that update every second)