InkWatchy battery life measurements
To eliminate all battery life related issues, or "It's just the design bro, trust me bro InkWatchy battery life won't last long bro" discussions, this higly accurate and complicated report will put the end to my misery.
Some notes about the experiment I performed:
Notes about the software:
- I disabled watchface modules, because depending on which one you use the battery life will change dramatically. While book, bitcoin, images modules will not impact battery that much, conway will, a lot
- InkWatchy at default enters "night mode" between 23 and 06 o'clock and wakes up in 45 minute intervals. I kept this functionality, but in the other hand I disable power saving mode which disables wakeups at all after 40% of battery is reached. So depending on your configuration with these variables, your results can be different too
- The commit that the software for compiled against is:
f2f5ed0b0253bbbe70a730297365fd8ab6fdcb52. All later comparisons and "My battery life is bad help me" situations should be compared with this commit - The watchy was not interacted with, so it's just a pure "update time" test, which is 90% of what the watchy is doing
- So in conclusions, this is a perfect scenario, no user input or changes, to make the measurements as objective as possible
About the hardware:
- I used this battery tester to truly test the battery capacity used in the test, until you test your battery with a similar device, you will never know it's true capacity. Furthermore I truly trust this tester, it never failed me
- The device I tested with was an old Watchy v2 from aliexpress, which was repaired many times. So does heating up components many times degrade their power efficiency? Idk, I'm not an engineer, just noting this
- The accelerometer was turned off, there was no step counting or anything
With that in mind, the battery I used was (and still is, tested both times) 63 mAh (We will translate the results later for the bigger batteries later). This is the capacity for down to 3.4V, below that I consider the watchy unstable, it may work, it may not, mine probably didn't, as the battery after disconnection was around 3.4 (It probably went up a bit, after disconnecting any power consumption from it). Just keep that in mind, maybe remove a few % from the results if you feel concerned about that
The test started at 1723649056 (Wed Aug 14 2024 15:24:16 GMT+0000) and ended at (As in, the watchy stopped stopped updating the time) 1723870920 (Sat Aug 17 2024 05:02:00 GMT+0000). This means we got 221864 seconds so 61 hours and 37 minutes.
Now let's calculate the average power consumption:
Average power consumption (mA) = Energy (mAh) / Time (hours)
so:
mA = 63 / (221864 / 3600)
mA = 1,022247864
Which checks out with any online calculator:
So what will be the battery life with a normal battery (200 mAh)?
So, with my in depth research of the average battery life (Of the Watchy v2, let me remind me once more):
Those are what the sellers say, I wouldn't and I don't trust those claims, but:
InkWatchy gives you 1 day and a bit more than the average (Which almost perfectly fits in the night mode no wake ups option enabled), or the bigger point I want to make is it's not worse, it just depends on your configuration ;)
What about a big battery?
This is a cool calculator, try it out for yourself: https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-battery-life
After some situations we decided to create this point of wiki to stop explaining each other again and again, this is a TLDR that both me and Michal agreed on:
tinywatchy does not wake up every minute like inkwatchy, but instead uses double tap gesture to wake up which saves power. And while using the firmware inkwatchy can use more power due to more complicated features being present. inkwatchy also doesn't count steps like tinywatchy does.
inkwatchy has option to wake up manually using button, it's labelled as "Wake up disabled" under power settings, in which case they'll use same amount of power unless you use inkwatchy's more hungry features
A bit more precise TLDR:
the big difference is because tinywatchy at default doesn't wake up every minute, it wakes up from gestures and then updates time
inkwatchy has such option to do that when clicking a button, it's labelled as "Wake up disabled" under power settings
Longer explanation:
It depends, but yes, tinywatchy is more efficient but in general use case of updating time which is 90% of the use case it doesn't matter, but by interacting with the watchy tinywatchy is more efficient because of the complexity of features in inkwatchy it couldn't be done as efficient as tinywatchy. It's also worth noting inkwatchy doesn't have accelerometer features, while tinywatchy optimised them a lot
A very calm conversation and a more technical explanation can be found here