Maximizing battery life on your device

[Alohamora]

Originally Posted by ProDigit

And lastly, audio/video books.
Some ebook readers don't support this feat,because audio books, and video books are very CPU intensive.
Try reading text-based books preferably. Picture based books second. And Audio/video based books last, if you want to save battery.

For those of us who read on a tablet, phablet, or phone, I would argue that audio books are more battery efficient because the screen can turn off completely during playback.

Even accounting for the difference between reading speed and spoken word speed, audio playback uses very little power compared to screen and backlight power.


I do sometimes turn off location, Bluetooth, WiFi and cell data and keep the backlight at the lower end of it's useful range. But beyond that, are any of these refinements needed or useful? It's not as if we're on an extended wilderness journey with only a solar charger available for power needs.

The built-in power management of current generation phones is remarkably good compared to just a few years ago. I pay attention to battery consumption because I'm geeky enough that it amuses me to do so. But I don't think I'd try to talk the average person into extreme battery conservation measures. Just use the device and enjoy what it can do.

[ZodWallop]

Originally Posted by ProDigit

From another perspective,
If you don't need the SD card slot, and can fit your library in internal memory, you could be saving battery by doing so.
If you're unaware of this, you may be using up more battery, paying for an SD card that can get lost, stolen with your device, or break down.

Nowadays you have to go out of your way to find a reader that supports SD cards, so if you have one, you probably bought it with that in mind.

But aside from that, I'm not arguing that they use some power. But when I'm looking at a device that can run weeks between charges, the extra amount used on the SD card is just worth it for the extra storage. My Aura has, what? 2.5GB for internal storage? It's not bad, but my 16GB SD card has 3GB of books on it now.

You could say that I don't need that many books and I should remove ones I've read. But with storage being that negligible, why bother? The minimal extra power usage is worth it to me.

Internal SSDs last longer, and if your device is stolen, you might already have $15-25 available for a new one (if you didn't invest it in an SD card).

That's one way to look at it. But then a Kobo Aura ONE costs $230 for 8GB of storage. The Kobo Aura ONE Limited Edition is $280 for 32GB of storage (prices from Kobo's website). You can buy a 64GB SD card for $25.

[Katsunami]

After two years, most batteries degrade heavily, anyways.

My current laptop (Dell Precision 7510 mobile workstation) has quite a large battery, and when I obtained this laptop about two years ago, I could get around 8 hours of battery life with medium usage (browsing, a bit of writing, some calibre organization/e-book editing) and medium screen brightness. Now, I can only get 4 hours of battery life. In another 2 years, it'll probably be down to one hour, and then the battery will stay there for a long time.

My old Lattitude (10 years old at the moment) dropped from 6 hours of battery life to about one hour in four years, and it is still at that point. Maybe... just maybe, I'll replace the battery and use the laptop as a backup system. (It runs Windows 10, has an SSD, and 8GB of RAM, and the C2D is still fast enough for general tasks such as browsing, mailing, and things like calibre, if need be.)

[j.p.s]

Originally Posted by ProDigit

You're forgetting the time it takes for a cpu to up and down throttle.
Basically, after every execution, the CPU goes into a sleep state, and disables cores. Every time you execute something, it goes out of this sleep state, which probably consumes just about as much battery, as the calculations it needs to make to render the new page.

No, I am not. That is all part of the energy cost of turning a page.

I have given up on you ever being willing or able to engage in actual discussion.

[Cinisajoy]

Originally Posted by Alohamora

For those of us who read on a tablet, phablet, or phone, I would argue that audio books are more battery efficient because the screen can turn off completely during playback.

Even accounting for the difference between reading speed and spoken word speed, audio playback uses very little power compared to screen and backlight power.


I do sometimes turn off location, Bluetooth, WiFi and cell data and keep the backlight at the lower end of it's useful range. But beyond that, are any of these refinements needed or useful? It's not as if we're on an extended wilderness journey with only a solar charger available for power needs.

The built-in power management of current generation phones is remarkably good compared to just a few years ago. I pay attention to battery consumption because I'm geeky enough that it amuses me to do so. But I don't think I'd try to talk the average person into extreme battery conservation measures. Just use the device and enjoy what it can do.

Unless I absolutely need them, I keep location and Bluetooth turned off on my tablets and phones. I keep the light turned down because it blinds me any brighter.

[j.p.s]

Originally Posted by sjfan

A micro SD card's sleep current is typically in the range of 0.2 mA drawn. If a Kindle with a typical 1420 mAH battery has 30 hours of continuous reading life, that's 47.333 mA of average draw; removing the SD card would decrease that to about 47.1 mA, saving you less than half a percent. Instead of 30 hours, you might get 30 hours and 7 minutes; it's not really going to be noticeable, and certainly isn't enough to impact how often you need to charge the battery.

All of these numbers are order-of-magnitude: maybe your SD card draws more like a 0.3 mA sleep current. But the basic story is the same: while there is a theoretical power draw there, there's not a big real-wold impact on reader battery lifespan (unlike with wifi or backlights, which can have a significant impact on battery life).

The following is not about whether or not removing an SD card is a worthwhile battery conserving strategy, but an extension of the above very good start at estimating energy costs. The calculations below are mostly based on those above with 1 additional order-of-magnitude value, that 1 hour of continuous reading per day will deplete a fully charged battery in 15 days, approximately equivalent to a discharge in 30 days with no reading. This corresponds to a sleep current of about 2ma (2ma for 50% in 15 full days of sleeping, 2.087 for 15 days less 15 hours, I will go with the latter).

720mah/1.887ma = 381.558 hours or about 21.5 extra hours on a charge, not counting the 7 minutes during reading.

[ProDigit]

Originally Posted by Alohamora

For those of us who read on a tablet, phablet, or phone, I would argue that audio books are more battery efficient because the screen can turn off completely during playback.

Even accounting for the difference between reading speed and spoken word speed, audio playback uses very little power compared to screen and backlight power.


I do sometimes turn off location, Bluetooth, WiFi and cell data and keep the backlight at the lower end of it's useful range. But beyond that, are any of these refinements needed or useful? It's not as if we're on an extended wilderness journey with only a solar charger available for power needs.

The built-in power management of current generation phones is remarkably good compared to just a few years ago. I pay attention to battery consumption because I'm geeky enough that it amuses me to do so. But I don't think I'd try to talk the average person into extreme battery conservation measures. Just use the device and enjoy what it can do.

A valid argument.
On a tablet, it might actually benefit to enable bluetooth headsets, and audio books, over text books; as bluetooth signal uses much less power than any kind of speaker (including wired headphones).



@jps:
There's a pro and a con to everything, and if I had made the list with only the first 2 or 3 points, people would be chiming in, and suggesting the other points I have already mentioned in this thread, and criticize that it was useless to make such a small list. So in a way, a man can never do right, with some people...
Then again, it's not the man writing, that did the wrong, it's just some people are more difficult than others in accepting other people's ideas...

[Cinisajoy]

Originally Posted by ProDigit

A valid argument.
On a tablet, it might actually benefit to enable bluetooth headsets, and audio books, over text books; as bluetooth signal uses much less power than any kind of speaker (including wired headphones).



@jps:
There's a pro and a con to everything, and if I had made the list with only the first 2 or 3 points, people would be chiming in, and suggesting the other points I have already mentioned in this thread, and criticize that it was useless to make such a small list. So in a way, a man can never do right, with some people...
Then again, it's not the man writing, that did the wrong, it's just some people are more difficult than others in accepting other people's ideas...

I have not read of anyone not accepting your ideas, just that most of your ideas have such a miniscule value as to not do much good if it makes the device almost unusable.

[Katsunami]

Originally Posted by Cinisajoy

I have not read of anyone not accepting your ideas, just that most of your ideas have such a miniscule value as to not do much good if it makes the device almost unusable.

Sounds a bit like the beginning days of the smartphone, where you could barely go one day if you disabled everything but making calls, and used GPS/Bluetooth/Internet for less than an hour or so. Nowadays, power efficiency is good enough to often easily make two days, with everything enabled including e-mails and GPS, and 4-5 hours of screen-on time during those two days.

E-readers never had any battery problems, IMHO (except if there was something wrong). As long as you keep Wifi off and the front-light to a reasonable level, the battery goes for two weeks of normal reading at the least.

[Deskisamess]

There are always going to be users who LOVE dinking with their Settings all the time. And there are those users who just use their devices and don't obsess over battery life and what options may affect it, especially for options they prefer to be enabled.

I don't care that keeping my Oasis screen light at 10 will give me a few more hours of battery life. I need the light all the way up unless I am reading in a dark room. I don't care that turning off WiFi will give me a few more hours of battery life. I prefer it to be left on so books are delivered with no extra steps. I want the Oasis to work for ME, not me working to squeeze longer battery life out it it.

I've known some users who sent their books back to the Cloud when they finished reading for the day. I never understood that behavior.

Everyone can use their devices the way they choose. At the end of the day, what does it really matter?

[Cinisajoy]

Originally Posted by Katsunami

Sounds a bit like the beginning days of the smartphone, where you could barely go one day if you disabled everything but making calls, and used GPS/Bluetooth/Internet for less than an hour or so. Nowadays, power efficiency is good enough to often easily make two days, with everything enabled including e-mails and GPS, and 4-5 hours of screen-on time during those two days.

E-readers never had any battery problems, IMHO (except if there was something wrong). As long as you keep Wifi off and the front-light to a reasonable level, the battery goes for two weeks of normal reading at the least.

On the normal reading is that your definition, my definition or the person that reads 15 hours a day. I think the last one just charges their reader every night.

[JSWolf]

The best way to conserve the battery is to turn off the Reader and don't use it.

[Deskisamess]

I don't think I've ever gotten 2-3 weeks of battery life on any Kindle I've used. Maybe the 2nd gen one that doesn't have a screen light.

And what is a "reasonable level"? for the screen light? 10 isn't bright enough for me in a normally lit room.

I open and close the cover on my Oasis numerous times per day, some days 15-20 times. I'm sure that effects my battery life also, the multiple wake-ups with the light all the way up.

I plug it in every 5-7 days on average, when it gets in the 15-20% range.

[JSWolf]

The problem with the Paperwhite series is that as they come (i.e., no jailbreaking) the light is not able to be turned off.

[sjfan]

Originally Posted by Deskisamess

I don't think I've ever gotten 2-3 weeks of battery life on any Kindle I've used. Maybe the 2nd gen one that doesn't have a screen light.

And what is a "reasonable level"? for the screen light? 10 isn't bright enough for me in a normally lit room.

Huh, interesting. For me, in a normally lit room I shut the backlight off; that's part of the appeal of e-ink devices. The backlight's only for when it's too dark to read normally.