Oasis Battery Issue

[pgilster]

Yesterday morning I plugged in my Oasis 3 to let it charge. Checking back late that night, I found it at 94 percent. Usually a full charge takes much less time. So I left it plugged in overnight and checked this morning. Same 94 percent, with the amber light on rather than the hoped for green.

It's true that I downloaded two large books just before doing this, so I know indexing was going on, but this doesn't sound right. I assume there is some problem with the battery communicating to the device what its actual charge is, but I have no idea how that works. Can someone explain to me what is happening? Is the Oasis battery getting into trouble, or is this a fairly benign problem? Thanks.

[Quoth]

Software just guesses from the voltage. On some devices the measuring software is on the cell charging control PCB.
Also as a cell ages it can be "fully charged" in the sense it can't safely be charged more, but have less total capacity. As a cell ages the charging is oven also done slower to avoid fire.

[j.p.s]

Originally Posted by Quoth

Software just guesses from the voltage. On some devices the measuring software is on the cell charging control PCB.

It's more complicated than that.

The PMIC tracks a number of parameters and the calibration factors can drift out of whack over time. It can be recalibrated by letting the battery to run down somewhat low then letting it fully charge.

It can also go off in the other direction. I have seen it as high as almost 110% but the kindle will clip such readings to 100%. This leads to people reporting that charge stays at 100% for a while then starts decreasing quickly.

[mergen3107]

I wouldn't pay too much attention to percentages below 10 and above 90 due to exponential nature of charging/discharging.

There is another thing that maybe Kindle was charged to 100% and then did not let to be charged more, and during this lock it dropped to 94% both times? What if you unplug and plug it back, will it go to 95?

[Quoth]

Originally Posted by j.p.s

It's more complicated than that.

Absolutely, I gave a lies for children version.
Yes, in fact in the years when I was designing and building gadgets
I only used NiMH. By volume when you are at AA, C and D* sizes they are now close to Lithium capacity especially after 200 full cycles. They weigh more. Lithium cells should be stored at 30% to 60% charge, but NiMH cells will keep for years if stored flat. You can still explode or set them on fire by faulty fast charging, but they don't burn so well as the Lithium. Even the primary single use coin cells can be persuaded to explode and burn.

[* Many NiMH C and D cells are using AA cells in a package, or sometimes the C cells in a D package. As an average AA is 2500mAH, a C or D of that capacity and lightweight is suspicious! There are various kinds of 9V pack, 6 cell (7.2V) or 7 cell (8.4V). The 6 cell can use AAAA cells. The 7 cells and some 6 use nearly rectangular button cells. The 9V, AAA and AAAA NiMH are best avoided. LiPoly is better for miniature packs.]

[pgilster]

Originally Posted by mergen3107

There is another thing that maybe Kindle was charged to 100% and then did not let to be charged more, and during this lock it dropped to 94% both times? What if you unplug and plug it back, will it go to 95?

No change when I unplug and plug back in. I like the earlier suggestions that I let it basically run the battery down and then do a complete re-charge. So I'll be using the Oasis a lot in coming days to get the battery close to 0 before trying the re-charge. It's a small thing but small things bug me ;-)

[HLS]

Originally Posted by pgilster

Yesterday morning I plugged in my Oasis 3 to let it charge. Checking back late that night, I found it at 94 percent. Usually a full charge takes much less time. So I left it plugged in overnight and checked this morning. Same 94 percent, with the amber light on rather than the hoped for green.

It's true that I downloaded two large books just before doing this, so I know indexing was going on, but this doesn't sound right. I assume there is some problem with the battery communicating to the device what its actual charge is, but I have no idea how that works. Can someone explain to me what is happening? Is the Oasis battery getting into trouble, or is this a fairly benign problem? Thanks.

I have the same issue. Will not charge above 94% and it drives me crazy. I even did a factory reset, took 2 days to download my books again, and still will not charge over 94%. i even tried draining the battery then charging. No change

[TheSmitty]

Originally Posted by HLS

I have the same issue. Will not charge above 94% and it drives me crazy. I even did a factory reset, took 2 days to download my books again, and still will not charge over 94%. i even tried draining the battery then charging. No change

Mine will get up to 98% but no more. It also discharges faster than my other kindle when sleeping. I love the form factor but hate, HATE the battery.

[Pjama]

I have to charge my Oasis every night - even when I only read a little during the day. I am ready to buy a new version with a PROPER battery, so come on Amazon, please do the right thing. I seem to do most of my reading with it plugged in these days - been hopeless since day 1 but truly terrible three years later. Screen just perfect, but the Oasis could be so much better with a battery like the KPW5.