Kobo Battery problem

[Pam R]

I have had my Kobo Clara a couple of years and used it a lot. I always got around 55 hours of reading per charge with no wifi or light on. The last couple of times I have charged it to 100% it has acted as normal until it gets below 50% then it drops more rapidly. Today it has dropped from 38% to 11% with only about 3 hours reading.

I took all my books off in case I had a bad one, put a few back on and cancelled automatic sync. I don't use the light and keep wifi off. Any ideas anyone?

I used to have a Nook for around 5 years with no battery problems.

[John F]

Did you try power cycling?

[Pam R]

Originally Posted by John F

Did you try power cycling?

Sorry, never heard of it.

[Pam R]

By the way, I switched of the automatically put to sleep option for my sleep cover, so it can't be that.

[John F]

Originally Posted by Pam R

Sorry, never heard of it.

Power cycling: turn it off and back on (not to be confused with sleeping and waking up.)

[Pam R]

Originally Posted by John F

Power cycling: turn it off and back on (not to be confused with sleeping and waking up.)

Thanks, yes, I have done that, no effect.

I got an update, wonder if that s
will make any difference.

[Pam R]

I have charged the battery up to 100%. let it run right down then charge up again to see if it recalibrates.

[Pam R]

Well since I last posted I have let the battery run right down on my Clara a couple of times. On the last charge I managed 41 hours of reading with no light on and the wifi only on to do one update. It still goes ok until just below 50% then drains faster. Although at higher percentages it suggests I could get well over 60 hours then this prediction reduces as I read more.

What sort of hours do other folks get with a Clara? It always annoys me when sites say up to two month, which means nothing because it doesn't say how much reading.

[4691mls]

Originally Posted by Pam R

Well since I last posted I have let the battery run right down on my Clara a couple of times. On the last charge I managed 41 hours of reading with no light on and the wifi only on to do one update. It still goes ok until just below 50% then drains faster. Although at higher percentages it suggests I could get well over 60 hours then this prediction reduces as I read more.

What sort of hours do other folks get with a Clara? It always annoys me when sites say up to two month, which means nothing because it doesn't say how much reading.

I think I read somewhere that those "two month" statistics are based on 30 minutes per day.

I don't keep track myself so I can't tell you how many hours my Clara lasts.

[porphyry5]

I have similar problem with Clara. Acts normally from 100% down to ~82%. Next time I turn it on its fully discharged, 1% only left.

I wonder if the battery doesn't contain 5 cells, of which only one is still good, because it charges from 0-100% now in about an hour, much faster than it used to. Mostly I'm hoping it gives up completely while its still under warranty, 3 months to go.

[Phil_C]

My Clara has exhibited similar behavior for the last six months. (It is 30 months old.) It seems OK until the charge gets down to about 30%. The next day it will be dead.

I know that the profile of Li-Ion batteries is to maintain good power for a long time, then drop off rapidly at the end. But this is different. And disappointing. My old Sony Readers were still going strong after 7 or 8 years. Sure, the charge didn't last as long as when new, but they didn't act like this.

For reference, a charge will now last me about 3 weeks. This roughly translates to 30-40 hours of reading. It's hard to pin down because the reader will at times be charging while connected to calibre.

It's a shock to have 30% charge when I go to sleep and find the thing dead the next day. This does not seem to bode well for longevity.

[davidfor]

Originally Posted by porphyry5

I have similar problem with Clara. Acts normally from 100% down to ~82%. Next time I turn it on its fully discharged, 1% only left.

I wonder if the battery doesn't contain 5 cells, of which only one is still good, because it charges from 0-100% now in about an hour, much faster than it used to. Mostly I'm hoping it gives up completely while its still under warranty, 3 months to go.

The battery is a single cell. From my experience, the discharge rate of Li-Ion cells is not linear. But, it shouldn't be that bad.

The real question is whether something is happening to use the battery while sleeping. I can state that my Clara HD does not do that. But, I have had some issues with syncing on it recently that have meant the sync runs for a long time and frequently doesn't complete. And that drains the battery. Plus doesn't let it sleep properly. Something like that would explain battery drain like you are reporting.

There have been other issues over the years related to problems with the reading part of the app that can be triggered by problems in some books. In those cases, something is left running when the book is closed and quickly uses a lot of battery. Restarting the device will kill the rogue process and the battery usage returns to normal. If you see this happen after a particular book, we can look at it to work out what is wrong. We may be able to fix the problem in the book and the problem will go away. And you can report the issue to Kobo so they can fix it from their end.

[Deobulakenyo]

Could be a problematic ebook?

[Pam R]

Thank you all for your responses. I have removed a couple of larger books and things improved a little. I will continue letting it run down completely for a couple more times to see if that makes any more difference.

[Pam R]

Originally Posted by porphyry5

I have similar problem with Clara. Acts normally from 100% down to ~82%. Next time I turn it on its fully discharged, 1% only left.

I wonder if the battery doesn't contain 5 cells, of which only one is still good, because it charges from 0-100% now in about an hour, much faster than it used to. Mostly I'm hoping it gives up completely while its still under warranty, 3 months to go.

Unfortunately I noticed this a couple of months after the 2 year guarantee that I paid £10 for had expired! I don't mind so much if I keep getting around 40 hours per charge.