KV charging issue at long-term usage

Eicca · 01-31-2021, 08:48 AM

Hello,
there is a problem occured during working on my alarm clock project (see other thread).
To my Voyage I have connected an USB-Speaker and a power connector with a y-otg-cable.

There are three files in filesystem (/sys/devices/system/...) to define the USB/charging-mode:
allow_charging
charging
mode

It is no problem to get the speaker and charging simultaneous to work.
mode 10 is otg-host: usb-port is powered by the kindle, speaker works without external power connector
mode 5 is otg-gadget: kindle can be charged. (allow_charging and charging have to be set to 1)

To protect the battery I keep the battery at 50%. If it is lower, I set to 1/1/5 (allow_charging/charging/mode). If it is at 50%, I set allow_charging to 0.

Now the problem: after some time the system do not observe the to these files written values anymore. So after half a day (or two or three days..) running the clock-script, charging stops and battery drains to zero.
I have checked, whether the files are set to the correct values and tried to "reset" the charging mode by setting to 0/0/10 and then 1/1/5 again, but nothing helped.

Do anyone have an idea how to solve this problem? My unwanted workaround would be rebooting the kindle with the script of my clock in autostart (not tested yet)..

Eicca · 02-13-2021, 03:43 PM

Hey,
I changed the fix threshold at 50% to an hysteresis (set to loading, when battery level is 50%, stop loading when it is 55%). I cannot explain why, but it works. No unexpected battery level since two weeks continuous operation of the script.

Eicca · 02-19-2021, 01:33 PM

Why it is not possible to edit a post of myself?

At the 17th day the strange behaviour occured again. I disabled the "battery save" code now, hoping with the built in charging logic allows problem free long-term usage. So the battery will be charged permanently to/ hold at 100%. But stable operation is a more desirable quality than lifetime of the battery in case of a alarm clock.

01-31-2021, 08:48 AM	#1
Eicca Junior Member Posts: 6 Karma: 538 Join Date: Dec 2020 Device: KV, PW4	charging issue at long-term usage Hello, there is a problem occured during working on my alarm clock project (see other thread). To my Voyage I have connected an USB-Speaker and a power connector with a y-otg-cable. There are three files in filesystem (/sys/devices/system/...) to define the USB/charging-mode: allow_charging charging mode It is no problem to get the speaker and charging simultaneous to work. mode 10 is otg-host: usb-port is powered by the kindle, speaker works without external power connector mode 5 is otg-gadget: kindle can be charged. (allow_charging and charging have to be set to 1) To protect the battery I keep the battery at 50%. If it is lower, I set to 1/1/5 (allow_charging/charging/mode). If it is at 50%, I set allow_charging to 0. Now the problem: after some time the system do not observe the to these files written values anymore. So after half a day (or two or three days..) running the clock-script, charging stops and battery drains to zero. I have checked, whether the files are set to the correct values and tried to "reset" the charging mode by setting to 0/0/10 and then 1/1/5 again, but nothing helped. Do anyone have an idea how to solve this problem? My unwanted workaround would be rebooting the kindle with the script of my clock in autostart (not tested yet)..

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02-13-2021, 03:43 PM	#2
Eicca Junior Member Posts: 6 Karma: 538 Join Date: Dec 2020 Device: KV, PW4	Hey, I changed the fix threshold at 50% to an hysteresis (set to loading, when battery level is 50%, stop loading when it is 55%). I cannot explain why, but it works. No unexpected battery level since two weeks continuous operation of the script.

02-19-2021, 01:33 PM	#3
Eicca Junior Member Posts: 6 Karma: 538 Join Date: Dec 2020 Device: KV, PW4	Why it is not possible to edit a post of myself? At the 17th day the strange behaviour occured again. I disabled the "battery save" code now, hoping with the built in charging logic allows problem free long-term usage. So the battery will be charged permanently to/ hold at 100%. But stable operation is a more desirable quality than lifetime of the battery in case of a alarm clock.

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