What am I doing to make my Kobo Clara HD battery drain so fast?

Aardman · 01-13-2021, 03:39 AM

My wife and I both got brand new Kobo Clara HD readers for Christmas this year.

I set both of them up at the same time.

Mine I loaded with most of the contents of my Calibre library - a collection of a few thousand ebooks. Hers I loaded a decent selection of her favorite authors.

Mine I read every night, for about 30 - 45 minutes. Hers she's read a few pages into the intro of one book and it's sat asleep ever since (she's reading a hardback book right now so isn't using her Kobo yet).

Her battery is still full.

My battery drains entirely in a matter of 3 days. Every evening when I open it the battery indicator is significantly lower. Hers, days go by, open it up, battery is still full.

We both have exactly the same style sleep covers, just different colors.

I don't run the screen all that bright, and I've turned off WiFi.

Wife claims it has to be because I have way more books on mine (it's about 2/3 full) but I don't buy that because that's just storage which I wouldn't think drains a battery.

I also refuse to accept the modest daily usage I put it through would cause that much battery drain either, and if it did, I would expect to see it while I'm reading, not the next day after it's been sleeping.

I do have several books "open" at the same time, books that are different percentages completed, but why would that have any impact?

Oh yes, both have the latest firmware.

I'm genuinely puzzled.

davidfor · 01-13-2021, 06:20 AM

With that usage pattern, the most like reason is a "bad" book. Some books have something in them that uses more CPU and hence battery. And leaves a process running in the background using power. I don't think I have seen a good explanation of what is wrong in the book that does this. But it is apparent as people open a book and read, then close it and the power is used. They reboot the device and it is OK until they open that book. The solution can be doing an epub-to-epub conversion in calibre.

The power used also depends on how fast you read. The device effectively sleeps between pages and uses very little power. The faster your read and more often you turn the page, the more power is used.

I think what format you read also affects the power usage, but, I have never truly tested this. I'd expect a PDF to use more CPU, but, I can never devide if a comic book (CBR or CBZ) will be worse than an epub. The comic will probably be a larger file, but, I don't know which will use more power rendering each page.

Aardman · 01-13-2021, 11:15 AM

I consider myself an average reader, not speedy by any means.

In fact about once every three - four pages on average I'll consult the built in dictionary.

I only read EPUB format. ONE time I spent about 1/2 hour with a really badly laid out pdf which I turned sideways and scrolled through and was shocked to see that DID almost totally drain the battery.

As for background processes, I turned off the wifi because the sync circle was constantly spinning and I couldn't stop it even by putting the reader through a sleep / wake cycle.

And where it really gets weird is, I also have a second hand Kobo Aura that does the same thing. I just assumed its battery was getting old so that's why I got the two new Kobo Clara's for me and my wife. Wasn't expecting to have the same problem with the new reader.

I've set the reader to shut off after one hour, but once it's asleep it never shuts down.

I though when the reader sleeps it stops all the processes? What could be actively draining the battery when it sleeps?

davidfor · 01-13-2021, 06:47 PM

The battery drain says that something is wrong. That could prevent sleep from happening properly. And the fact that you are seeing the same problem on two devices, says you should look a the common factor. Which is probably the books (unless you have a super-power that is to drain batteries).

As a simple test, when you next stop reading, restart the device and put it to sleep. That will stop any rogue process and initialise everything. If there is no big power drain, it suggests the problem is a book.

Something else to do is check the device actually sleeps. There is usually some light leakage under the cover to see when the light turns off. And make sure there is nothing around to interfere with the magnetically operated switch. A lot of people have complained about devices not sleeping and draining power to discover the sleep was being blocked by something.

Aardman · 01-14-2021, 03:18 AM

Thanks.

I'm onto the not sleeping problem and have eliminated that one, but have yet to try putting restarting it before putting it to sleep.

Just tonight I unplugged it after it was fully charged, then found some books I wanted to load so plugged it back in to transfer the books. When finished, the battery was HALF DRAINED!

I'm beginning to think I got a lemon, but will try the restarting before sleeping to see if that makes any difference.

davidfor · 01-14-2021, 04:10 AM

Quote:

Originally Posted by Aardman

Just tonight I unplugged it after it was fully charged, then found some books I wanted to load so plugged it back in to transfer the books. When finished, the battery was HALF DRAINED!

Just to check. It was fully charged when you plugged it in to the PC. You added a few books and disconnected it. It then imported the books and when finished, the battery level was 50%

Is that correct?

If so, it is sort of expected. The the book import process uses a lot of power. The device searches for new books, checks if the existing books has changed and removes them from the database, then it opens each new book to get the metadata and ToC, updates the database, then generates covers for three of them (to display in the "My Books" tile). And for epubs, that is opening the book and rendering the start to get the first page. If you put enough books on the device in one batch, it could run the battery out.

Add to the above, if a book is causing the problem you are seeing, opening it for the above can actually trigger the problem.

Nightflyer · 01-14-2021, 12:04 PM

I’ve had my Clara HD for almost a year. No issues.

Today, it drained from over 50% to nothing in about 12 hours while sitting inside my bag like it always has. I hope this is a one time occurrence.

Troubleshooting: Two things different recently.
1. Had a PDF file as my current read, have never done that before.
2. Turned off both header and footer.

Charging now to check behavior tomorrow.

Aardman · 01-14-2021, 12:10 PM

Not exactly. After moving the books over I unmounted the reader but didn't unplug it. It was connected to power the whole time. After it was unmounted and it came back to the home screen, that's when the battery was half drained. This all happened while it was plugged in.

Are you suggesting one of the books currently on the reader has some kind of issue that is causing this? I've added books plenty of times, including a HUGE batch when I initially loaded it, and never seen any impact on the battery. When it's plugged in, it's plugged into a power source, so I wouldn't expect any drain whatsoever from adding books.

I could do a complete epub to epub conversion and then reload the reader again from fresh, maybe even a total restore, but hate to go that route if there's a simpler way to identify the culprit.

Aardman · 01-14-2021, 12:12 PM

Quote:

Originally Posted by Nightflyer

I’ve had my Clara HD for almost a year. No issues.

Today, it drained from over 50% to nothing in about 12 hours while sitting inside my bag like it always has. I hope this is a one time occurrence.

Troubleshooting: Two things different recently.
1. Had a PDF file as my current read, have never done that before.
2. Turned off both header and footer.

Charging now to check behavior tomorrow.

Mine drained completely after about 1/2 hours worth of trying to read a PDF, but I turned it sideways and was doing all kinds of zooming and scrolling. I deleted it and no longer fiddle with PDFs.

Aardman · 01-14-2021, 12:13 PM

One other thing I've noticed - I though maybe I could stop the issue by setting it to shut down after an hour.

It never shuts down, just sleeps.

4691mls · 01-14-2021, 12:30 PM

Quote:

Originally Posted by Aardman

Are you suggesting one of the books currently on the reader has some kind of issue that is causing this?

Yes, that is possible. It happened to me once on one of my old Sony readers. Once I finished reading the most recently added book, I then deleted the book and the problem went away.

In my case, I had added only that one book shortly before the problem started so I knew it had to be the one.

JSWolf · 01-14-2021, 04:11 PM

@Aardman,do you recall what books you've added before the problem started? I you do, you can delete all of them and if the problem has gone, you can load one, give the Kobo time to show the problem or not and keep doing it until you find which one is causing the problem. if you cannot remember which ones you added, you can look on the Kobo at the file dates for the books and see which ones were loaded on that day, take note, plug into Calibre and delete them.

Aardman · 01-15-2021, 12:22 AM

Actually, no.

Over the years I've built a somewhat substantial Calibre library. When I got the new reader I just transferred them all in bulk to the new reader and it's been having problems from the outset.

I'd go through the hassle of EPUB to EPUB conversion, if that would solve the issue, and reloading the entire shebang, but since Calibre keeps the original as well as the new conversion, with no option to delete the original, it would double the size of my library.

Ripplinger · 01-15-2021, 01:05 AM

Calibre renames the original file as .original_epub, so it's a simple matter to just delete those files once you're satisfied that the newer epub is well formatted. But definitely open the book to make sure the conversion didn't mess up formatting before deleting the original copy.

If I was having that problem, I'd remove everything off the reader except for the current book I'm reading and test it awhile. If the excessive battery drain stops, then start transferring books back in smaller batches and using the reader for a bit between each transfer. That way you can narrow down which book (or books) is causing the problem.

I really wouldn't convert the entire library epub to epub and hope that fixed it.

Aardman · 01-15-2021, 02:46 AM

Because of the folder structure used in Calibre it is anything but simple to to remove the original epub as that requires opening literally hundreds of folders one at a time to find the file.

It may be that I will have to resort to removing everything and adding them back in batches, but that's vexing.

01-13-2021, 03:39 AM	#1
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	What am I doing to make my Kobo Clara HD battery drain so fast? My wife and I both got brand new Kobo Clara HD readers for Christmas this year. I set both of them up at the same time. Mine I loaded with most of the contents of my Calibre library - a collection of a few thousand ebooks. Hers I loaded a decent selection of her favorite authors. Mine I read every night, for about 30 - 45 minutes. Hers she's read a few pages into the intro of one book and it's sat asleep ever since (she's reading a hardback book right now so isn't using her Kobo yet). Her battery is still full. My battery drains entirely in a matter of 3 days. Every evening when I open it the battery indicator is significantly lower. Hers, days go by, open it up, battery is still full. We both have exactly the same style sleep covers, just different colors. I don't run the screen all that bright, and I've turned off WiFi. Wife claims it has to be because I have way more books on mine (it's about 2/3 full) but I don't buy that because that's just storage which I wouldn't think drains a battery. I also refuse to accept the modest daily usage I put it through would cause that much battery drain either, and if it did, I would expect to see it while I'm reading, not the next day after it's been sleeping. I do have several books "open" at the same time, books that are different percentages completed, but why would that have any impact? Oh yes, both have the latest firmware. I'm genuinely puzzled. Last edited by Aardman; 01-13-2021 at 03:42 AM.

01-14-2021, 12:04 PM	#7
Nightflyer Connoisseur Posts: 76 Karma: 2122502 Join Date: May 2020 Location: Asia (from USA) Device: Meebook M6, Kobo Clara HD	I’ve had my Clara HD for almost a year. No issues. Today, it drained from over 50% to nothing in about 12 hours while sitting inside my bag like it always has. I hope this is a one time occurrence. Troubleshooting: Two things different recently. 1. Had a PDF file as my current read, have never done that before. 2. Turned off both header and footer. Charging now to check behavior tomorrow. Last edited by Nightflyer; 01-14-2021 at 12:10 PM.

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01-13-2021, 06:20 AM	#2
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	With that usage pattern, the most like reason is a "bad" book. Some books have something in them that uses more CPU and hence battery. And leaves a process running in the background using power. I don't think I have seen a good explanation of what is wrong in the book that does this. But it is apparent as people open a book and read, then close it and the power is used. They reboot the device and it is OK until they open that book. The solution can be doing an epub-to-epub conversion in calibre. The power used also depends on how fast you read. The device effectively sleeps between pages and uses very little power. The faster your read and more often you turn the page, the more power is used. I think what format you read also affects the power usage, but, I have never truly tested this. I'd expect a PDF to use more CPU, but, I can never devide if a comic book (CBR or CBZ) will be worse than an epub. The comic will probably be a larger file, but, I don't know which will use more power rendering each page.

01-13-2021, 11:15 AM	#3
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	I consider myself an average reader, not speedy by any means. In fact about once every three - four pages on average I'll consult the built in dictionary. I only read EPUB format. ONE time I spent about 1/2 hour with a really badly laid out pdf which I turned sideways and scrolled through and was shocked to see that DID almost totally drain the battery. As for background processes, I turned off the wifi because the sync circle was constantly spinning and I couldn't stop it even by putting the reader through a sleep / wake cycle. And where it really gets weird is, I also have a second hand Kobo Aura that does the same thing. I just assumed its battery was getting old so that's why I got the two new Kobo Clara's for me and my wife. Wasn't expecting to have the same problem with the new reader. I've set the reader to shut off after one hour, but once it's asleep it never shuts down. I though when the reader sleeps it stops all the processes? What could be actively draining the battery when it sleeps?

01-13-2021, 06:47 PM	#4
davidfor Grand Sorcerer Posts: 24,907 Karma: 47303748 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	The battery drain says that something is wrong. That could prevent sleep from happening properly. And the fact that you are seeing the same problem on two devices, says you should look a the common factor. Which is probably the books (unless you have a super-power that is to drain batteries). As a simple test, when you next stop reading, restart the device and put it to sleep. That will stop any rogue process and initialise everything. If there is no big power drain, it suggests the problem is a book. Something else to do is check the device actually sleeps. There is usually some light leakage under the cover to see when the light turns off. And make sure there is nothing around to interfere with the magnetically operated switch. A lot of people have complained about devices not sleeping and draining power to discover the sleep was being blocked by something.

01-14-2021, 03:18 AM	#5
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	Thanks. I'm onto the not sleeping problem and have eliminated that one, but have yet to try putting restarting it before putting it to sleep. Just tonight I unplugged it after it was fully charged, then found some books I wanted to load so plugged it back in to transfer the books. When finished, the battery was HALF DRAINED! I'm beginning to think I got a lemon, but will try the restarting before sleeping to see if that makes any difference.

01-14-2021, 12:10 PM	#8
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	Not exactly. After moving the books over I unmounted the reader but didn't unplug it. It was connected to power the whole time. After it was unmounted and it came back to the home screen, that's when the battery was half drained. This all happened while it was plugged in. Are you suggesting one of the books currently on the reader has some kind of issue that is causing this? I've added books plenty of times, including a HUGE batch when I initially loaded it, and never seen any impact on the battery. When it's plugged in, it's plugged into a power source, so I wouldn't expect any drain whatsoever from adding books. I could do a complete epub to epub conversion and then reload the reader again from fresh, maybe even a total restore, but hate to go that route if there's a simpler way to identify the culprit.

01-14-2021, 12:13 PM	#10
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	One other thing I've noticed - I though maybe I could stop the issue by setting it to shut down after an hour. It never shuts down, just sleeps.

01-14-2021, 04:11 PM	#12
JSWolf Resident Curmudgeon Posts: 73,896 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	@Aardman,do you recall what books you've added before the problem started? I you do, you can delete all of them and if the problem has gone, you can load one, give the Kobo time to show the problem or not and keep doing it until you find which one is causing the problem. if you cannot remember which ones you added, you can look on the Kobo at the file dates for the books and see which ones were loaded on that day, take note, plug into Calibre and delete them.

01-15-2021, 12:22 AM	#13
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	Actually, no. Over the years I've built a somewhat substantial Calibre library. When I got the new reader I just transferred them all in bulk to the new reader and it's been having problems from the outset. I'd go through the hassle of EPUB to EPUB conversion, if that would solve the issue, and reloading the entire shebang, but since Calibre keeps the original as well as the new conversion, with no option to delete the original, it would double the size of my library.

01-15-2021, 01:05 AM	#14
Ripplinger 350 Hoarder Posts: 3,574 Karma: 8281267 Join Date: Dec 2010 Location: Midwest USA Device: Sony PRS-350, Kobo Glo & Glo HD, PW2	Calibre renames the original file as .original_epub, so it's a simple matter to just delete those files once you're satisfied that the newer epub is well formatted. But definitely open the book to make sure the conversion didn't mess up formatting before deleting the original copy. If I was having that problem, I'd remove everything off the reader except for the current book I'm reading and test it awhile. If the excessive battery drain stops, then start transferring books back in smaller batches and using the reader for a bit between each transfer. That way you can narrow down which book (or books) is causing the problem. I really wouldn't convert the entire library epub to epub and hope that fixed it.

01-15-2021, 02:46 AM	#15
Aardman Member Posts: 17 Karma: 10 Join Date: Jan 2021 Device: Kobo Aura HD	Because of the folder structure used in Calibre it is anything but simple to to remove the original epub as that requires opening literally hundreds of folders one at a time to find the file. It may be that I will have to resort to removing everything and adding them back in batches, but that's vexing.

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