new Oasis battery life

[HLS]

Originally Posted by HarryT

As has been said before, that figure means absolutely nothing in isolation. How many hours reading have you done in the week? WiFi on or off? Frontlight set to what level?

3 hours or less wifi bluetooth off light around 10

[HarryT]

3h a day, or 3h in total during the entire week?

[cvkemp]

I have read for about 3.5 hours since I drained the battery and recharged over night, and my battery is only down to 90% left. I keep the WIFI, and bluetooth off. I keep the lights at 8-10.

[HLS]

Originally Posted by HarryT

3h a day, or 3h in total during the entire week?

about 30 minutes a day sometimes 40

[ProDigit]

Originally Posted by HarryT

Using it until you get the low battery warning does not fully discharge it. You can't discharge it to the point at which damage might occur.



The relationship between voltage and battery charge level is device-specific (or, more accurately, battery-specific), and the firmware does need to calibrate it. This is well-established.

No need for calibration. It knows any voltage below 2.8V is essentially cut off, and 4.2V is high.
It calibrates from reading the voltage and power drop over time.
When using the battery, the drop from 4.2 volt to 3.5V will take about the same time as from 3.5V to 2.8V, and that's all it needs to know.

[j.p.s]

Originally Posted by ProDigit

No need for calibration. It knows any voltage below 2.8V is essentially cut off, and 4.2V is high.
It calibrates from reading the voltage and power drop over time.
When using the battery, the drop from 4.2 volt to 3.5V will take about the same time as from 3.5V to 2.8V, and that's all it needs to know.

First, I agree that at a given load, lithium cell voltage is directly related to state of charge, but voltage decreases as load increases and can increase when current decreases, so battery state of charge is more complicated than than a simple voltage measurement.

Second, I do not know whether the current state of battery management benefits from or uses any on board self-calibration.

But it is simply not true that a constant average load causes the battery voltage to decrease linearly with time.

Let's say a hypothetical "idle" but "awake" Kindle uses 140 milliwatts. That is not some official number, but it is close enough for illustration purposes. The Kindle power supply converts the battery voltage to the constant voltage that the Kindle needs to operate.

For the battery to supply 140mw requires:

33.333 ma @ 4.2 V
40.000 ma @ 3.5 V
50.000 ma @ 2.8 V

so the voltage drop per unit time is continuously increasing and there is no way that
"the drop from 4.2 volt to 3.5V will take about the same time as from 3.5V to 2.8V". For an actual battery, the above calculations are too simplistic and optimistic, because as current increases, more power is lost to the internal resistance of the battery. The total mah extractable from an alkaline cell is much much higher at 1 ma than 500 ma.

[gal_amy]

Originally Posted by Atunah

I'd ecstatic if my O2 would only use 37% in 4 days.



You guys need to stop thinking in days or weeks. It means nothing if you don't also look at the time the device is actually used for reading. And then there are other variables while doing the reading. . I turned off the accessibility setting that gave me percentage. I am not looking at it anymore. I know I have to charge every 2 days. Or after I read 2 books. Long ones that is. . I like to charge before I get to 33% down.

Good idea!



Sent from my iPad using Tapatalk Pro

[HLS]

Originally Posted by HarryT

Keep it in aeroplane mode and it won’t shift off 100% charge on standby. If you leave WiFi on, it’s talking to Amazon and draining the battery.



Have you tried making the font a little bolder? That should allow you to use a lower light level. I find personally that with the boldness on “2” I can very comfortably read with the front light off in a moderately well-lit room.

I already do all that it is on airplane mode 24/7, I still have to charge at least once a week

[HLS]

Man I lost 60% battery life in 4 days but I forgot to turn off the wifi the past 24 hrs.

[Sonicboom]

Originally Posted by kcladyz

Man I lost 60% battery life in 4 days but I forgot to turn off the wifi the past 24 hrs.

Really? :/ That dammed wifi, but if I turn off it it last 2 books in English..its ok for me..

[ProDigit]

I usually charge weekly, when I'm not even using the device :/ .

[DuckieTigger]

Originally Posted by ProDigit

I usually charge weekly, when I'm not even using the device :/ .

I usually don't use the device either while charging. A good time to charge is when you are sleeping.

[HarryT]

Originally Posted by DuckieTigger

I usually don't use the device either while charging. A good time to charge is when you are sleeping.

It charges so quickly that I really don't see what the fuss is about. It'll charge from 70% to 100% in about 20 minutes, in my experience.

[DuckieTigger]

Originally Posted by HarryT

It charges so quickly that I really don't see what the fuss is about. It'll charge from 70% to 100% in about 20 minutes, in my experience.

The fuzz is mostly buyers remorse, I think. Otherwise it doesn't make any sense. The experience alone should be enough to be happy with the device, no need to hunt down flaws. If anything, I can only complain that I don't have enough time to read to have to charge every other day. I wish I could, but then nobody has enough time to read.

[cvkemp]

The charge time is really fast. Also, I am not seeing the battery drain most are talking about. I have not charged my Oasis for a week now and it is still at about 86% charge. I have been reading it an average of 40 minutes a day also. Now, I have not added any books in the last two weeks, and I have not had the Wifi on for more than a few minutes in the last week.