Noticeable Battery Drain on KOReader - Kobo Clara HD

[Frenzie]

Anyway, it's definitely not common to empty more than a few percent per day though regular reading, but the precise scenario you described (i.e., down from 100-80 in a couple of days) is a bit of a special case on many devices.

Do you use a sleep cover?

[Ciantic]

Originally Posted by NiLuJe

We don't suspend while reading. Nickel does. There's (part of) your page-turn speed trade-off .

(I am somewhat vehemently *against* implementing something like that, because I *like* that behavior. That said, the framework is there, because it's implemented on PocketBook. This is possibly a fairly deep rabbit hole with a lot of potentially bad interactions, though, but patches welcome ).
.

If I'm reading this correctly it would affect battery life only while reading. I'm interested in figuring out how to implement "suspend while reading" because to me changing pages need not be quick, all I care about is battery life.

There are conflicting threads here, some accusing Koreader of wasting battery while in sleep, which is another issue altogether. It could be just some hardware quirk sometimes when sleep fails to turn off something.

I have Kobo Clara BW and I suspect Koreader does use more battery than Nickel... however, there is no going back to Nickel it's so bad UX-wise. Koreader is the only choice!

[mergen3107]

Originally Posted by Ciantic

I'm interested in figuring out how to implement "suspend while reading"

IIRC, this is already implemented with the "Auto power save" plugin.

[Ciantic]

Originally Posted by mergen3107

IIRC, this is already implemented with the "Auto power save" plugin.

Setting was turned off by default, but the plugin was enabled by default.

Anyone else wandering here years later, here is how to enable it:

Go to Gear icon -> Device -> Autostandby timeout (set this value)

If it's not visible you might need to go to:

Wrench/Screwdriver icon -> Page 2 -> More tools -> Plugin management and make sure "Auto power save" plugin is enabled

[strangelove42]

I'm at about 4% battery use while reading. No standby timeout. Full screen refresh every 3 pages.

[Ebookus]

It would be interesting to see how much time of actual use you all get from one charge. I am getting about 10-12 hours on kindle

[strangelove42]

Reporting battery stats (Awake since last charge) for two charges using diff settings:

Auto-standby Off, 3-page Refresh

Total time: 17:28
Consumed: 63%
Change per hour: 3.61%
Est remaining time: 7:13 (~25%)

Auto-standby On, 6-page Refresh

Total time: 23:24
Consumed: 60%
Change per hour: 2.56%
Est remaining time: 7:25 (19%)

Except for the very first page turn after opening a book (sometimes very slow), I didn't notice the latency with Auto-standby On. When I wasn't doing much highlighting, I was consuming as low as 1.7% charge per hour.

Battery life is not necessarily a priority for me. I never use it away from home. I'd more like to prioritize the longevity of the device. What puts more strain on the device: the extra battery use or the powering up and down of the auto-standby?

[lumping-sugar66]

I've been experimenting with the KOReader for about a week now, and the battery statistics on my Clara 2E is indeed concerning. I'm seeing a reliable ~2-2.5% drop per hour when the device is sleeping. I woke up to 80% battery for the past 3 days where I left the device at 100%.

I'm experimenting with bluetooth drivers, so I may be doing weird things to the battery usage; I actually started by attributing this drain to running bluetoothd continuously. But today I killed bluetoothd and went back to the old state of the program, the drain persists. in in 6 hours, the battery drained by 18% (Change rate is 2.93%) all while the device was asleep.

I'll monitor this situation and provide more of insights.

[lumping-sugar66]

Originally Posted by lumping-sugar66

I've been experimenting with the KOReader for about a week now, and the battery statistics on my Clara 2E is indeed concerning. I'm seeing a reliable ~2-2.5% drop per hour when the device is sleeping. I woke up to 80% battery for the past 3 days where I left the device at 100%.

I'm experimenting with bluetooth drivers, so I may be doing weird things to the battery usage; I actually started by attributing this drain to running bluetoothd continuously. But today I killed bluetoothd and went back to the old state of the program, the drain persists. in in 6 hours, the battery drained by 18% (Change rate is 2.93%) all while the device was asleep.

I'll monitor this situation and provide more of insights.

Yeah. It's bluetooth. turns out bluetoothd running is hogging the battery regardless of whether the device is on or off. With all services killed, I can confirm overnight I've seen 0% power drain.

[Apollyon202]

I have a Libra 2, wifi is off mostly, although I also noticed some higher battery drain. I read somewhere, when you turn on wifi, bluetooth is also turned on because they are on the same chip (?).
I try it out and kill bluetoothd as well, yet not sure how, but I guess it's in the terminal.

Edit:
Oh, I don't have bluetoothd as I don't do any experiments with bt. Oops my bad.)
Though I have 1-2% power drain in sleep mode. Maybe I should just thinker with the settings a bit more. Otherwise koreader works perfectly and flawlessly. (Libra 2 rev 2)

[Frenzie]

I don't know if killing bluetoothd would necessarily do much one way or the other as long as lsmod shows various bt* things.

Yeah. It's bluetooth. turns out bluetoothd running is hogging the battery regardless of whether the device is on or off. With all services killed, I can confirm overnight I've seen 0% power drain.

You'd have to check the logs. It could be using energy while sleeping. The frontlight can do that if you don't turn it off. But it could also be preventing the device from sleeping at all, basically the same but worse.

[lumping-sugar66]

The following routine eliminates this drastic battery drain due to bluetooth:

hciconfig hci0 down
pkill hciattach
pkill bluetoothd
rmmod -w /drivers/mx6sll-ntx/wifi/sdio_bt_pwr.ko
rmmod -w  ./uhid/uhid.ko

I have tested each component and all of them contribute to the drain in some small way adding up to almost ~3% per hour. Killing them eliminated the entire drain. Right now I have 12h40m sleep time on my device with 0.00% change per hour.

FWIW, it's not related to this thread anymore but I wrote this for my page turner plugin. A complete procedure on how to turn bluetooth on and off properly is in the shell scripts of the repository below.
https://github.com/onatbas/bluetooth.koplugin

[Aleron Ives]

Dare I ask why KOReader has Bluetooth running by default when the device is sleeping?

[lumping-sugar66]

Originally Posted by Aleron Ives

Dare I ask why KOReader has Bluetooth running by default when the device is sleeping?

Because I disabled the pkill instructions

(I was working on a bluetooth plugin)