Kindle Battery Surgery [Success!]

[geekmaster]

NOTE: Many images on pages 1 and 3 require that you be logged into a mobileread account to see them. I am attempting to fix that problem now.

Okay, I have taken the "kindle battery surgery" pictures requested in another thread, and here they are..

Not sure which kindles these fit, other than PW2 and PW3. Unlike earlier kindles with 4-pin battery modules (some with labelled clock and data wires, these are 3-pin battery modules (perhaps using "1-Wire" protocol?).

This is the battery from a PW3 (identical to that in my dead PW2, whose battery is now in my PW3), with the outer label peeled off, and the metal "tray" removed. It was inflated (like most dead LiPo batteries). I tore the foil pouch opening it. I hope the gases I inhaled were not TOO toxic.

Here is a cropped closeup from that the photo above, showing circuit details.

This is with the internal LiPo battery flipped over to reveal more of the circuit board inside the battery module. The metal battery tabs are spot-welded (though on the K2 battery they are soldered to the circuit board).

EDIT: The wrinkles you can see on the deflated battery foil jacket (above) give an indication of how puffed up it was when still inflated.

This is cropped closeup from the photo above, showing more circuit board details.

This is a closeup of the circuit board, taken from another viewing angle, so you can see under one of the battery tabs. I could not get a good focus (cellphone camera) when I tried to photograph the text on the ICs. The sunlight needs to hit it "just right" to even see the text on the chips (too small to read with MY naked eyes). That blue-marked black band on one battery tab just looks like a shrink-wrapped label to me.

The battery in your Oasis photos looks different to me. However, I suspect that the same method may be useful to replace its INTERNAL LiPo cell with a cheap replacement, keeping the circuit board and battery module frame intact.

BTW, instead of uploading photos to Imgur (or wherever) as in the past, this time I uploaded them to my MobileRead profile, where I created a photo album in my user control panel. Those photos are embedded above. No worries about external links suffering bit-rot (as in some of my OLD posts here, now with dead photo links in them) this way, eh?

[geekmaster]

I plan to replace that dead Sony LiPo cell shown in my previous post above with something cheap, like this:

3.7V 1200mAh 25C Lipo Battery $3.23 (Free Shipping)



http://www.ebay.com/itm/like/371474331938

Hopefully, the little circuit board inside the battery module will identify it as an authentic kindle battery, so the system will boot up. We shall see, won't we?

I have a K2 in this condition (worse actually -- the swelled battery split the side of the case open, breaking some of the tabs that snap the cover together). I will do "battery surgery" on it too...

If that works, I may try a somewhat physically larger (higher capacity) LiPo, but it needs to fit in the battery frame. A tiny battery may need recharging more often, but still probably less often than my cellphone...

[geekmaster]

And here are a couple of photos of my inflated K2 battery, which is literally THREE TIMES its original thickness (bulging the front and back surfaces of the K2 case, and splitting the case open on one side):

Battery serial number fuzzed, just to confuse amazon.


And the connector side. As you can see, the older kindles had four battery pins, unlike the three shown in the PW2/3 battery post above. On a K3 battery those middle pins actually have "clock" and "data" (or similar) labels printed on them. They are unlabelled on this K2 battery module.

What is not visible in these photos is that the center of the battery is inflated most, on both sides. The photos appear more inflated near the edges, just because of how the light is reflecting from the battery wrapper. The center is three times as thick as the corners.

In the future, I will remove the outer label, and take more photos of the inner circuit board and LiPo battery pack, and I will post them here.

[geekmaster]

If you plan to do any "LiPo battery surgery", let this video serve as a warning:



Hint: It ain't over 'til it's over...

Of course, he is damaging his multi-cell LiPo battery one cell at a time in that video. The kindles only have a single cell (so only "one" fire, eh?)...

But really, as long as you do not poke holes in that foil LiPo battery pouch they all come in, you should be reasonably safe.

[geekmaster]

More LiPo-liscous fun:

[geekmaster]

I took the K2 battery apart, and I took photos, but all the USB jacks on my computer have busy hard drives plugged into them. I could go get one of my 10GHz wireless docking bays, but meh, bedtime. I will upload the photos in the morning...

This time I took photos at various stages of peeling off the sticky parts (the plastic wrapper/label and rather thick aluminum foil or really thin aluminum sheets, however you define the difference).

This battery module had some other unfamiliar brand of LiPo battery in it. It also has Kapton tape insulating it, which is difficult to peel off the "strain relief" cloth backing, so I will leave it and snip the metal leads close to the LiPo battery, and solder the replacement onto those metal tabs.

As I mentioned elsewhere, a really small new battery should behave identical to a really old (but good) original battery. As lithium batteries age, increasing parts of the material becomes inactive (and the inactive part is literally called "rock content" in the industry).

So a small LiPo from a rechargeable device should be no different than what is in an old kindle battery -- the charger circuit and firmware should just work.

I wonder if it is worth bothering to fuzz all the identifying numbers on all the parts -- probably not -- are they going to void my warranty on this used K2 or something?

[blkhawk]

The Oasis battery has a 3-pin connector as well. its hidden below the ZIF flatflex connector.

[knc1]

Originally Posted by geekmaster

More LiPo-liscous fun:

In the over-all shots of this person's set-up, they missed one point:
They should have been standing up-wind rather than down-wind.

[geekmaster]

Originally Posted by Dr. Drib

Please take a few moments to read our Posting Guidelines, in particular the part about the maximum image size allowed (600x600 pixels). Images that violate those guidelines will be deleted.

It is every member's responsibility to read our Posting Guidelines and follow them.

Thanks.

I did read the guidelines when I joined (and again later, when I had a question). I thought the limit was on WIDTH (to prevent funky over-width formatting for the thread page), not height. I formatted all these images for 600-wide (or less). I will go back and re-read the guidelines...

Hmm... My images were all 600 wide when uploaded. The mobileread Albums CONVERTED the tall ones to 768 tall (and much narrower than 600).

QUESTION: If your guidelines say the max height is 600, then WHY does the mobileread Album upload CONVERT large images down to 768 height (which the images you deleted WERE, 768)?

EDIT: Okay, I resized my images from the 768-height imposed by your albums, to the 600-height your guidelines require, then I re-uploaded and re-inserted them into the post from which you deleted them.

[geekmaster]

Here are the photos I took last night while disassembling the bloated K2 battery pack (all converted to 600x600 or less, before uploading to my mobileread photo album):


Top of label peeled loose. That torn tab was there already, from the battery swelling (which also damaged the kindle case).


Flipped over so the back label of the plastic wrapper is visible.


Peeled and naked. Not easy to get the tabs started. I should have waited to trim my fingernails until AFTER peeling this wrapper, eh? This time I did not use a knife to start the corners, like that punctured PW2 battery I did previously...


Plastic frame flipped up so you can see how the LiPo battery fits inside the pack.


Opened up. There is more ink on the adhesive than remains on the LiPo battery.


A closeup of the internal LiPo battery labelling (what was left after peeling off the aluminum sheets). And you can see how inflated that foil pack is too.


Those metal tabls should be fairly easy to cut close to the battery, with a pair of heavy-duty scissors.


That kapton tape is pretty thoroughly bonded to the cloth, so I did not peel it off any more than you see here.

As you can see, the K2 battery packs have four terminals, unlike newer kindle batteries that have only three terminals. Perhaps they switched from i2c to 1-wire protocol?

The aluminum sheets that cover the front and back of the battery pack (under the label) probably contain and distribute the battery heat so that the circuit board can more accurately measure it, for safe charging. This must be taken into consideration for any replacement LiPo cell as well, for safety. Those sheets are about the same thickness as aluminum soda (or beer) cans, so replacements could easily be made from such salvaged aluminum.

EDIT: I wonder how you are supposed to type that URL for the wikipedia "i2c" page. Click that link to see the URL in the web browser title bar. On my browser, I see a superscript '2' character (even when I hover over the link in my web browser). Using hard-to-type characters in a URL is not user-friendly -- especially on an older smartphone that does not display such superscript characters...

[geekmaster]

I took the K2 battery module apart even more. I borrowed a LiPo battery module (single cell 3.7v) from a small quadcopter. I put it in the kindle and plugged the kindle into my computer -- nothing --- no USB device detected. Then I plugged it into a USB charger --- again nothing --- no kindle power LED, frozen "critical battery" eink display...

But after a few minutes on the charger, everything changed:


The quadcopter LiPo has its own internal "protection" circuit board (and it is too thick to put the K2 cover back on). But this is just a test, until I find a LiPo that fits better.


And into the kindle it goes! Notice (above) that the plastic battery module frame is flexing -- it may need internal support (like those aluminum sheets) to make good contact with the battery connector.


It's alive! Well, at least the power LED came on after it was plugged into a USB charger for a few minutes. It does not yet show up as a USB device when plugged into a PC.

And a few minutes more charging time, another attempt at seeing if a PC can see it as a USB device...Yes! Umm... Wait, what? It showed up as a "lab126 RNDIS" device. Hmm... More time on the charger -- now it shows up as a disk device, but with no partitions (probably just that 0MB "low battery" fake disk device you can see mentioned in the GPL source code).

I have noticed that the voltage across the LiPo battery terminals has been increasing, so the kindle IS charging it. That is a good sign. But I need to let it charge longer before I can test it in any useful way...

Progress has been made. Hopefully this K2 was not destroyed when the swelled battery bulged out the front and back of the kindle case...

EDIT: Just to show how SMALL that LiPo battery really is, the "GIANT" black plug you see at the bottom of that bottom photo above is a microUSB cable. And you know how much fun those are to get plugged in right-side-up in a dark room in the middle of the night (without damaging the jack), eh?

[geekmaster]

I just noticed that this K2 (while still plugged into the USB charger) is now showing the kindle GUI framework. It has 25 books on it. The settings menu shows that it is still registered, but the previous owner had the radio turned off, so perhaps it was derigistered at amazon. I will make a backup copy of the userstore partition before I turn the radio on...

Yay! It works! Now to unplug it from the charger to see if that battery is acceptable to the kindle. I will test it, then do a restart from the settings menu, and test it again...

Umm... the LED only stayed on (amber) a few seconds after unplugging it -- BUT it did NOT come on after replugging the power, until I jiggled the battery module. Yeah, it flexes too much wihout extra support.

VERY carefully (so as not to wiggle the battery, on battery power only (no USB cable): "menu / settings / menu / restart". It restarted. It displayed the GUI framework (showing all those books), but with a popup warning that my battery is running low and I should connect it to a charger.

YES! My "battery surgery" was successful!

Any old cheap LiPo battery CAN impersonate an authentic amazon battery (with a "brain" transplant -- i.e. that little circuit board harvested from the old dead battery).

Enjoy!

EDIT: Though I wonder if this tiny little 500mAh battery can last long, especially when it has been unused and uncharged for a couple of years... ESPECIALLY if I use it to play videos with my kindle video player, eh? But for just book reading? Probably a lot longer than using my smartphone to read books, for sure...

[knc1]

Originally Posted by geekmaster

- - - -
EDIT: Though I wonder if this tiny little 500mAh battery can last long, especially when it has been unused and uncharged for a couple of years... ESPECIALLY if I use it to play videos with my kindle video player, eh? But for just book reading? Probably a lot longer than using my smartphone to read books, for sure...

That is twice the storage capacity shown on the Oasis (internal) battery.

I haven't seen anything on how large the storage capacity is of the battery that is in the case.
The case is probably just an excuse for the (required) external battery pack.

= = = =

I just did some quick, crude, measurements of a 6000 mAH LiPo, 3.7v cell I have handy and a K5 case - -
It looks like you could hide that battery in one side of the case.

So it should fit inside a K2 case - or any case for that matter.
The K2 would be easy - it has small cutouts on the left size of the case for the cover clips.
That is where I brought out the serial port wires on the one I have bricked here.
But it should be just as easy to run battery cables out the cutouts.

[geekmaster]

The charging LED is now green. My multimeter says the battery is now at 4.19V (a "normal" full charge for a 3.7V LiPo when not under load). So that pretty much means not only was the "surgery" a success, but the "follow up" diagnosis indicates great health for this previously dead (sold as "broken") K2.

[geekmaster]

I just figured out how to keep the battery module plastic frame from flexing inward, to keep the four connection pads on the frame in solid contact with the kindle battery jack:


Rotate the LiPo 90-degrees!

A stroke a genius, eh?

EDIT: Those four pin labels that are "almost" readable, are (top to bottom in above photo) "- C D +", where 'C' and 'D' are almost certainly "i2c Clock" and "i2c Data".