Originally Posted by knc1
There was one other bit of information in the original post: "bricked for years".
The type of battery in the Kindle does not last forever in the fully (or nearly fully) discharged state.
I would not be surprised if the O.P. needed a new battery by now.
The ideal storage condition for lithium ion batteries is at 40% charge, but no more than 70% charge (60% recommended maximum, for a margin of safety).
Putting a kindle in storage with a full battery charge will also shorten its lifespan. The kindles contain a "shipping" script (also available in diags on some models) that partially discharges the battery to prepare it for shipping or storage.
There is a very interesting easy to understand document on lithium batteries that I read years ago, and I am glad to see that it still exists. I recommend reading this:
And now I see that it has an updated version available as well:
One interesting thing is that lithium ion batteries like those used in a kindle start aging immediately after manufacture, and will die of old-age even unused in original packaging, so it does not help to buy a spare battery "for later". It is best to use a freshly manufactured replacement battery.
Most rechargeable lithium ion batteries are only good for about 5 years past manufacture, but newer ones may last up to 10 years before needing replacement (if stored partially charged). But if stored undercharged or overcharged, they can have a much shorter lifespan.