Quote:
Originally Posted by voidoid
I would be interested to know if you come to some definite conclusion - ie problems with the files can impact battery life. If this is so then it could be the answer for a few problems.
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Quote:
Originally Posted by dakini
my suspicion ... and why i asked the questions about the file ... is that the size of the file does affect battery drain. i have an 8MB epub I sideloaded, and I noticed incredibly fast drain on my battery. I've had a couple other kepubs that have been missing some of the chapter anchors and so they load large chunks -- 150 pages or so -- and they seem to drain the battery a lot faster than normal sideloaded epubs.
so, in my experience the size of the file, and how much of it gets loaded at a time, seem to affect drain, which I think is what Mrs. Often is also noticing on her device.
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Okay, so! It was most definitely the kepub file that was causing the problem. I threw it off and loaded its epub equivalent and the battery stayed at 100% for most of yesterday, until I changed some of the epub's CSS and reloaded it twice causing processing and restarts (so battery usage) when I was finished the battery was at 95%. The battery has stayed at 95% for over 15 hours now, with the epub in question in memory (so I didn't go back to the home screen) and in sleep mode with the light on (well, off, but memory knew it had to switch it on when device was awoken). The 15+ hours includes one hour of reading with the light on (light is always on its very minimum).
This sounds more like what the battery usage should be like! So I'm happy.
Some notes: the epub is only 574KB. However, it is missing a lot of chapter marks. The first 7 chapters are contained in one file and are thus seen as one chapter, so in the kepub version, those are all loaded into cache. That's 255 pages (if I recall correctly) at the ready at any one time. So I would say not surprising that that drains the battery. Unless there's more wrong with the kepub file, but I doubt it. If you'd like to test/see for yourself: the book is David Baldacci's "
Absolute power". I got it for about €0.39, but unfortunately the Christmas sale for it has ended.
Quote:
Originally Posted by dakini
personally, I always power down rather than put in sleep mode, unless I know I'm returning very shortly (like after fixing a cuppa). and I always return to the home screen. i don't know that either of these really change the consumption, but if there were a way to minimise battery consumption when not reading, then turning it off, or else putting it to sleep at the home screen (rather than with a book loaded) should minimise the drain.
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Seems like all the extra hassle isn't actually needed! Well, not for epubs anyway (unless they're HUGE, but I don't know exactly what of an epub is put in cache or not). But your careful battery saving manner would help a lot for kepubs I think.
Quote:
Originally Posted by jusmee
I can think of no mechanism by which this can happen. I suspect something else caused the problem.
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Well, it was strange to me at first too, but a while back this was explained to me on this forum somewhere when we were discussing what the difference was between battery use in sleep mode vs. in off mode. I can't find the thread right now but I'll add it if I find it later on.
Quote:
Originally Posted by dakini
in the Netherlands, do you have battery stores that will rebuild internal batteries? I've seen them occasionally ... stores like this: www.mdsbattery.co.uk/ i've had such a place rebuild a laptopn battery before for half the price of a new battery, and it worked fine. |
Thanks for the tip! I didn't know things like that existed. I'll look around for such a store next time I have a real battery malfunction.