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Old 12-29-2019, 03:13 PM   #32
mattzz began at the beginning.
Posts: 17
Karma: 10
Join Date: Feb 2014
Device: pw, pw2
Originally Posted by Junket View Post
PW4 has a 1500 mAh battery, PW/2/3 are usually said to be 1420 - 1470 mAh. If you can suspend a significant amount of time as several posters suggest is possible to set (above, here) & minimize wifi use, a month or more on battery should be an attainable goal.
The math still does not check out, even if you spend a considerable amount in STR (like ~90%).

I am using the Kindle as a clock device only (I know, sounds weird - but hey...) which updades the display every minute and does nothing else.

The device will be in STR state for ~55 seconds each minute and active for about 3-5 seconds. 5 seconds consuming 100mA for 60 times an hour results in ~8mAh. So IN THEORY the best we can get is a runtime of ~200 hours. And that is not taking account for any wifi reconnects/updates. So even in best case I think we are far away from a attaining a runtime of a month.

Different story for an hourly update (~50 days runtime) but I guess for a clock the user acceptance factor would drop quite severly. ;-)

So from my understanding the 1440 rtc wakups per day are killing the idea of a long life battery clock.

Creating the header below should forestall aggressive checks for firmware updates when wifi is enabled:
touch /var/local/system/SKIP_UPDATE_CHECK
Does this also work for an old PW running
I added to my /etc/hosts, pointing at 127.0.01...

Better yet to stop the todo process next to lab123_gui and other processes that are not needed in my case.

Setting the cpu governor to powersave also reduces current draw (from ~110mA with "ondemand" to 50-80mA with "powersave" according to gasgauge-info) but things will take longer then.
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