Portable device screen/battery/power woes. Questions!
September 20, 2018 5:57 PM   Subscribe

Do most or all portable (i.e. battery-powered) devices absolutely require a minimally-functioning battery to work properly? I ask because my ca. 2012 ebook reader's screen is now going black about a minute after turning on, and continues to do the same after disconnecting power and then reconnecting.

Background: I only use this e-reader in bed for 10 to 60 minutes, once a day. Several years ago, when I pushed in the small power button on the device's bottom edge, it pushed in further than it should have, breaking loose from what connected it inside to the device, and since then that button has been non-functional (still in the, I suppose, "on" position). Not too much of a problem for me, however, since all I had to do was to connect it via the micro-USB to USB cable to the USB-to-plug-in-wall adapter to turn it on, and unplug to switch off. As soon as I unplug the micro-USB cable from the device, it has no power and is completely turned off.

This morning, however, I was reading when suddenly the screen went dead (though the blue power light remained on). Puzzled, I unplugged the micro-USB cable after waiting 10 seconds, then plugged it back in. I resumed reading, but then the same thing happened after about a minute, and again when I tried another time. Could this be an indication that the internal battery has reached such a low level that it no longer has enough juice to power the minimal requirements for screen operation for more than a minute? (The screen has recently been going off from time to time, but has easily been revived by simply hitting the "Enter" button on the face of the device.) I ask about the battery specifically because I know that some devices -- like Sony Walkmen -- have screens that will not function unless the battery has a certain minimum amount of juice.

If anyone can provide an explanation of what is most likely going on here (and any possible solutions?), I would be grateful. I am on an ancient pre-intel Mac, and fear that most tablets on the market will not connect to my ancient machine, so it might be hard to find a replacement! (I load new books onto an SD card with my current device, and never need to actually connect it to the computer.)
posted by tenderly to Technology (7 answers total)
What brand and model is it?
posted by procrastination at 6:00 PM on September 20, 2018

posted by tenderly at 6:21 PM on September 20, 2018

That device has a lithium-ion battery. It can only be recharged a certain number of times before it can no longer hold a charge. I suspect, as you do, that the battery is dead. I found a user manual for it as well, and it also says that if the battery life seems short, the battery might beed to be replaced. Unfortunately, there doesn't seem to be a thriving community around this device, so I couldn't find any instructions on changing the battery or even what kind of battery it would take.

In your shoes I might just accept that it is dead and then try to carefully open it to see if I can extract the battery and get a new one. The battery might be a commodity part if you can get in there and see.
posted by procrastination at 7:10 PM on September 20, 2018

Have you tried contacting them?
posted by oceanjesse at 11:34 PM on September 20, 2018

Re: contacting them: I last contacted them a couple of years ago, and even then they made it clear that this device was ancient history to them, and they could not offer much if anything in the way of support. I seem to recall there being other models (from other brands) that resembled this one, so it was very likely just a case of their rebranding of another China-made device for the N. American market.

I realized that I should try powering up the device using an external battery pack (with USB power input) I had kicking around somewhere. So after hunting around and finding it, I plugged in the device, it powered up and then... stayed on! So it looks like I may be able to keep on using it with the external battery.

An odd thing I have noticed is that while the device power goes off as soon as I unplug it from the AC connection, it stays on for a while after unplugging it from the battery pack, which leads me to believe that the battery is (still) being charged when connected to the battery pack, but not when connected to the wall socket.

If anyone has any insight into why there are these differences between how the device operates on AC vs. DC, I'd love to hear it!
posted by tenderly at 2:04 AM on September 21, 2018

If the behavior changes when charged from the battery pack, that points to an issue that's developed in your AC charger setup. (The way your device works is identical when charging via AC as via DC, it's the wall plug that converts the AC to DC.)

The fact that the device used to turn off immediately after unplugging implies that the battery wasn't charging (or just barely charging), and you were getting just enough power to run the device. Now, I'd guess you're getting a bit less power, and the device may be making up the difference by drawing down what little power is in the battery, until it can't keep up and shuts off. The battery pack is probably providing enough power to both run the device and charge the battery, which is why it runs when unplugged.

Are you using the same USB cord, or is it possible that the USB cord attached to the AC adapter is bad? I've damaged multiple cords by repeatedly kinking them while reading in bed, so this is my first guess.

Also, is the wall charger the one that came with the unit, or does it at least have an equivalent current rating? If it's a cheap one, or one designed for charging a low draw device (like a bluetooth headset, cheap fan, etc.), it may be underrated, or have recently degraded. Try swapping it out with a different charger. (The manual I found shows it draws up to 1.2A, so you want one with at least that much current, and a higher rated charger is fine.)
posted by yuwtze at 8:08 AM on September 21, 2018

Thanks for that response, yuwtze!

I think you have identified the source of the problem: the USB extension cable that runs from the micro-to-standard USB cable plugged into the unit to the wall charger has indeed developed multiple kinks in recent months, and when I run the device off the battery, I only use the micro-to-USB, not the extension cable.

Last night I read from the device (using the battery pack) for around an hour, after which the device reported that the internal battery was fully charged and would provide 5+hours of use. Since I cannot turn the unit off, it remained on after disconnecting from the battery pack, and was, of course, drained of power when I woke up.

I just connected the unit directly to the wall charger (no kinky extension cable) and the screen did not black out after a minute, so I think I just need to get another USB extension cable.

There is one issue that persists: For the past week or so, the device no longer remembers my auto-rotate or screen brightness preferences. I have auto-rotate turned off in the prefs, but it now auto-rotates anyway if I tilt the device slightly. This has persisted through all the device-powering configurations that I have reported. Any idea what may have caused that?
posted by tenderly at 3:13 PM on September 21, 2018

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