Unrealistic Battery Life Claims for eReaders?

Kobo Aura One Battery Drain Issue

How many ebook readers have you seen being advertised with 1-2 months of battery life per charge?

Yeah, that includes pretty much all of them. B&N claims the Nook Glowlight 3’s battery can last up to 50 days on a single charge. Amazon says Kindles can go 4-8 weeks between charges, depending on the model.

But are those realistic claims?

Or is it mostly just a marketing tactic that tries to make battery life seem better than it really is?

To me, it’s clearly the latter. I don’t know why ereaders with E Ink screens continue to be advertised with these unrealistic battery life claims.

They should be judged by the number of reading hours, not some ridiculous math formula based on reading 30 minutes per day for X amount of days with X amount of variables.

Why should reading for 30 minutes per day be defined as the official way to determine battery life?

I don’t know why they can’t just say how many hours the battery will last like other types of electronics.

Go look at laptops, tablets, phones, Bluetooth speakers, etc—and you’ll typically find an estimated number of usage hours to determine battery life.

But for some reason E Ink ereaders continue to get by with convoluted battery life claims.

Saying an ereader’s battery can last 1-2 months or 4-6 weeks per charge is a deceptive way of putting it. They used to go by the number of page-turns, saying an ereader’s battery could last for up to 10,000 page-turns. That was even more ridiculous.

Most tablets on the market these days could last “weeks” on one charge if you only use them 30 minutes per day. It’s not an honest, accurate representation of overall battery life.

From my experience the battery on devices like the Kobo Aura One and Kindle Oasis 2 typically last for 15-20 hours per charge, though that’s at the lower end compared to other models.

Some iPads have batteries that can last 13 hours per charge so that’s really not much of a difference, and that’s based on continues web browsing over Wi-Fi. If you had Wi-Fi turned off and used it like an ereader the battery would last even longer than that.

So why do E Ink ebook readers continue to advertise unrealistic battery life claims? The only way a battery is going to last for more than a month is if you’re hardly using the device at all.

24 Responses to “Unrealistic Battery Life Claims for eReaders?”

  1. Is it reasonable to think that it goes back to before ereaders were backlit, and you were comparing looking at an eink screen (using no power to remain static) and a LCD screen (where its always doing something). Even then, you’d have to look at page turns, but, there was a NEW stark difference in the technology.

    That tagline of weeks has kind of been grandfathered in, but, now they have to qualify it better…hence the 30min, light setting set to 10, etc…

    Also….I guess they assume that most people are reading alot less than they are doing things on tablets and phones.

  2. I’ve been a voracious reader for nearly 60 years, averaging better than 400 books a year. I currently use a Boox i86 ereader, and it’s about the ninth or tenth ereader I’ve owned. The best I’ve done for time on ANY ereader is about five to seven days on a charge. As you suggest, using page turns or 30 minutes of reading a day is completely unrealistic to the point of being hyperbole. Hopefully, the makers of ereaders will reconsider and devise a more factual marker to determine battery life.

  3. IMO-Realistically most readers that actually read on an e-reader probably read for an hour or more on average…a phone, maybe 20 min to 40 min while in line, waiting for something, on a bus or train.
    Battery claims are definitely s t r e t c h e d!

  4. Yes. I think the same. It’s different when I read an epub (more time), than reading pdf, and less doc or docx at boyues and KPW (not epub, just mobi, or converted from app, calibre, or downloaded from Amazon), but less battery for pdf. Without screen light.

  5. I’ve been asking myself the same question for a while. The only reason I’ve been able to come up with is that for the manufacturers of ebook readers, claiming month-long battery life may give them a bit of a marketing edge when trying to compete with tablets and smartphones.
    I fully agree that battery life expectancy should be expressed in terms of hours of reading time.

  6. Testing publications need to apply (and clearly state) their battery-life test procedures. Only when a review source applies the same testing procedure to various e-readers will we be able to compare fairly.

    You could do that if you wanted to… couldn’t you?

  7. Ingo Lembcke, EU, Germany Reply March 8, 2018 at 4:09 am

    Frontlight should not use much power, as it is LED, as far as I know.
    With Kindle one thing is not totally unimportant: even when sleeping, they connect once a day to WiFi, for up to 15min. So even when not in use, they use power. As I have 2 Kindles (one for German store, one for US-store), I was surprised to pick up my unused Kindle after a few weeks and it was nearly drained.
    Both Kindles connect to WiFi once a day when not in use, one at 9 am, the other 6 pm. Give or take. My guess is, if at that time WiFi is off, they would drain power, regardless, trying without success. Might be, they try more than once a day, but between 10 pm and 7 am WiFi is off (Router setting, very handy).

    As I now own a Fingbox, I set that to send an email for every WiFi connect/disconnect. A few devices connect daily or twice daily, TV, Kindle, but so far no other eReaders (Tolino, an older Sony T1) I own.

  8. At least in my experience, e-ink battery-life trends have been declining over the last 5 years or so. My PW1 was about 25 hours while my KA1 was about 18 & the Oasis2 was about 14.

    It would be nice if the industry put as much effort into reversing that trend as they do crafting their misleading battery life results.

  9. One hours worth of reading on my Nook Glowlight Plus (with the light off) reduced the battery charge from 57% to 55%. That would give me about 50 hours worth of reading time on a full charge.

    Battery life varies depending on the age of the device and its battery, so an ereader several years old (like mine) would have a shorter reading time than a brand new one.

    I can well believe that a new ereader would be capable of 60 hours of reading time, or two hours a day for 30 days. That is, a month. I suspect that two hours a day for a month is on the high end of the average for ereader use.

    • You need to test from full to drained. Battery meters aren’t that accurate, especially on Android. There’s no way the Nook’s battery is going to last for 50 hours of reading time.

      • There’s no way the Nook’s battery is going to last for 50 hours of reading time.

        The 50 days claim for a Nook battery is based on a half hour of reading a day, which would make 25 hours of reading. The claim has never been 50 hours.

  10. It’s all marketing… even in the PC/smartphone/tablet/drone/camera/anything-battery-powered markets, battery life claims are ALWAYS inflated by using a very specific set of tests that are rarely indicative of real world use. A perfect case in point is the upcoming Snapdragon series of laptops. So far, only Lenovo, HP, and Asus have announced upcoming products. The Asus NovaGo purportedly will get 22 hours of battery life. I doubt that will translate to real world use though. Will it get significantly more battery life than an X86 laptop? Yup. 22 hours of on-screen time? Not a chance. I think the numbers with every day, real wolrd use will be significantly closer to 12 to 14 hours of on-screen time, which is still phenomenal, but nowhere near their claims.

    My wife has a Moto E4 Plus. Motorola’s marketing for the device claims 2 to 3 days of screen-on time. Not in real world use, buddy. She uses the phone for calls, social media, a bit of browsing, the occasional map, and one low end game… VERY typical real world use. She has no problems getting a whole day out of a full charge, but she’s at around 40% life after that. Not even two days is going to happen here. It’s only a day off of their claims, but that’s somewhere along the lines of a 50% inflation of battery life claims. E-readers are no different. We’ve NEVER gotten a month out of ANY e-reader we’ve owned. Usually, we have no problem getting 10 days between charges, though. My wife reads a WHOLE lot, though.

  11. Oasis 2 battery life varies a lot depending on what is enabled. Screen lighting is 12 LEDs and if set to bright they do suck power. Other power users are Bluetooth, Wi-Fi or 3G communications enabled and book indexing if you load a bunch of books into memory. Battery life is good if all the optional drains are disabled. With all on the battery charge does not last for long.

    The same has been true since the Kindle Keyboard, K4/K5 and original Kindle Touch with the illuminated covers which were run by the internal reader battery. I have the illuminated covers for all of them and if the light is used, along with communications left enabled, the battery life will not be any where near Amazon;s claims.

    Screen lighting has gone from one LED with the original lighted covers to 4 LEDs on the PW models to 6 or 8 on the Voyage to 12 on the Oasis 2. No idea of the battery drain but 12 LEDs almost certainly need to suck a lot more power than the single LED did. I personally would prefer that makers quit trying to make the readers thinner and thinner and maximize battery capacity. As is I normally carry a backup USB battery pack if I am going to be using a reader away from home. A 3200 to 6000 Mah battery pack is small enough to be a minor burden and can recharge a reader several times. My latest 6700 Mah Anker battery pack is only a bit larger than a Snickers bar.

  12. The battery life Amazon advertises is a lie. Within 3-5 days my Oasis is down to 50% or lower charge. I keep wifi off unless I need it to sync and light level 10-14 depending on time of day and I only read 30 minutes to an hour a day. If Amazon advertises 8 weeks on level 10 30 minutes a day I should at least get 3 weeks on my level of reading. I also know I am not the only one annoyed at this. Who reads on a light level of 10? way way too dark

  13. My original kobo aura touch lasted at least 3 weeks at 4 hrs average reading , my kobo aura one lasts 4 to 5 days . And has been replaced twice

  14. I currently bought a Boox note S, the spec for battery capacity should be 3000Mah. The battery last only 3 days after fully charge, so go I download a 3rd party battery saver apps to save battery, from there I found the actually battery capacity is only 1000Mah. Guys, do me a favor if your e reader is able to download 3rd party apps, please help me check if your battery capacity to find out if the ereader manufacturer are cheating. This is unfair to us, imagine 2/3 is missing!!!

    • It’s more likely than not the app is wrong. The battery on Android readers is going to last like a tablet if you’re using it like a tablet, but if you keep WiFi off and only use the device for reading the battery lasts a lot longer. Some 3rd party apps also tend to drain battery a lot more, even when not using them.