Aura H2O battery problems, fast draining while reading cbz files

[hkckoo]

hello, I was wondering if anyone else had this issue, battery drains 5-10% in hour while reading comics/manga, altough the images are high-res (up to 3000px), could this be a problem?
I am quite disappointed in the device, everyone said how ereaders last weeks (if not months) on charge and then you learn that the device has only like 1000mah battery and it lasts two months on one charge if you are reading 30minutes per day.
but back to my problem. today battery drained from 20% to 0% in like 30 minutes, this cannot be normal?
//i also should mention that while reading big cbz files 200-500MB in koreader, the reader tends to freeze a lot and I have to restart it numerous times. I found that after restart the battery tends to be down by 2-5% is this a faulty reader?

[PeterT]

I cant help but think you are experiencing issues caused by the device having to resize the graphics images down to the resolution of the device itself.

[GeoffR]

Originally Posted by hkckoo

but back to my problem. today battery drained from 20% to 0% in like 30 minutes, this cannot be normal?

I don't know about the CBZ files and image resizing, but just beware that the battery meter is not a linear measure of battery charge, and it can drop off quite quickly at the bottom of the range.

Reading on my Glo (ePub or KePub books only) it would be quite normal to go from 20% to 0% in 30 minutes or less, but going from 80% to 60% would take about 10-15 hours. (I generally get about 40 hours reading time per charge in total.)

Edit: Another thing to consider is how quickly are you turning pages? The reading times that are commonly reported are probably based on reading books like novels that are mainly text, where the page is turned once or twice per minute and the device is essentially asleep between page turns. If you are flipping through the book much faster than that, or using scroll/zoom to move the viewport around between page turns, then I think you could expect the battery to drain at a faster rate.

[frostschutz]

If it wasn't so much work, I'd slice each comic page into its individual tiles whenever possible. However that would increase the number of "pages" and Kobo isn't great at handling CBZ in the first place. One database entry per page when I last tried it.

Handling large graphics could be optimized (basically what's being done when you look at some gigapixel graphic sites, or Google maps, slice it into smaller units) but nobody will invest that kind of effort into a PDF/comic reader so most likely every time you zoom/scroll it will go back to square one and re-resize and re-crop the original big image and the CPU will struggle with that.

Long battery life is only if the device does nothing whatsoever which is the case when reading books, once the page is displayed [which in itself doesn't take much power for just text] it can twiddle its thumbs until the reader decides to flip the page which might be a long time later...

[bookaquarius]

I read a lot of manga in cbz format on my H20 and the battery life seems normal. Granted, manga is mainly black and white, some files can go up to 100++MB depending on the file format and resolution. So far, I have no problem opening 200MB file size with kobo default reader. The only thing I don't like is the zooming feature, it doesn't work well.

Perhaps you want to consider compressing the images in the comic file to make the overall size smaller. I am currently slicing webtoons so I can keep and read them on my H20. I tested the file (about 4 chapters worth, did not convert the images to BW) and it works fine. Not sure how it works when the file gets bigger, will know soon once I'm done with the first arc of the story.

What about the screen brightness of the device? Mine was set between 0-5% for most time depending on situation. Brightness also affects the battery life. Oh and also whether you have your wifi on all the time.