Oasis 1 - anyone found an ok internal battery?

[cajhin]

The Oasis 1 is still my favorite reader, but the internal battery is shot.
I've bought 4 batteries so far, they range from "bad" to "ridiculously bad".
Did anyone find a battery that works well, and comes at least close to the original 8-10h runtime?

I'd appreciate any recommendations, thanks


VARIOUS OPINIONS
While I'm at it, maybe other KO1 aficionados are interested in details.

- the best of the bad is a Losoncoer from Aliexpress (30 bucks). It lasts ~4h, and never calibrates right (stays at 100% and 0% for much too long).
- CS Cameron Sino is the most common on ebay. I've had 2, both really bad (~2h, even worse calibration, and % drops in large chunks, like 80 to 50 in 1 minute)
- an "original", I'm sure fake, looks like the original Amperex. Lasts 30 minutes, jumps from 100 to 0 when I turn on wifi. This matches my experience with other batteries, when someone makes illegal fake items, they don't care at all for quality.

I'm disappointed by Amazon. If only they had a store where they could sell replacement batteries, so I can keep using their gadgets for as long as I want...

The "split battery design" looks like a commercial and critical failure, but I'm in the camp that really likes it. I get a super light device (Amazon says the '22 kindle is the lightest kindle ever - not true, not even close). I have to recharge it less often than anything else. Only have to snap it out of the cover when I read, and snap back in at the end of the day. It's protected, and I actually enjoy the snap process because the magnets are beautifully done.

Probably noone will ever try that design again, which makes the KO1 a one of a kind, and I like special things
Besides, I've got an 8" Kobo One, but I strongly prefer 6", and I really prefer buttons. Amazon doesn't do buttons anymore

Changing the internal battery is pretty easy, I can now do it in like 3 minutes.

TIP: the ifixit manual is wrong IMO. Do NOT attempt to force bend the firm case sides with a spudger to release the clips of the grip cover (it's hard, and I broke a clip doing that). Instead, simply use a thin blade to slowly and carefully pull the thin end of the grip cover off from the adhesive tape, without bending the cover too much. Then you can simply slide out the clips/pins from their holes.
The hardest part is pulling the battery from the tape, without tearing it.


The flaw in the design is that the small internal battery degrades quickly. While the cover goes through 1 charge cycle every couple of weeks, the internal one goes through 6 cycles, and degrades 6x faster. Now I have a spare cover with a like-new battery and don't really need it, while the internal one should be replaced every 3 years (if you could buy replacements).

A compound flaw is that the !@#$ software will not allow you to shut down the device, sleep mode only. If you don't use it for a few weeks, it will be empty the next time. If you don't use it for longer, the battery will be totally deep discharged, which damages the chemistry. In my book, that's a big [+] for the Kobo, which you can shut down (and it boots much quicker, too).

[Quoth]

Likely the batteries (cells really) are too old. They go off with age.