[knc1]

Hmm...
You must have missed my very long and tedious explanation of "Why".
That is Too Long, so Don't Bother to read.

*) You do not freeze the battery, you freeze the Kindle. Whole, complete, unopened (which is sort of the reason a person does this without taking the battery out).

*) You do wrap the Kindle before, during and after the freezing. The wrapping of a light, soft, cloth does not affect the temperature changes. It does minimize the chance of condensation when removed from the freezer.

*) The why this works, when it does work, is not changes to the battery, it is changes to the internal hardware of the battery management chip while at less than its designed minimum temperature.
This process does not actually change either the battery or the battery management chip when within its its normal temperature range.
If you let your Kindle sit around until the battery is deader than the normal conditions the battery management chip can handle, you get to do this again.

PS: Often the reason for no progress in re-booting beyond the 30% point is while the system does filesystem check and repair. That is, there is no progress indicator to show what is being done. File system check and repair on eMMC is very slow and very power hungry. Hence, the fairly frequent "deader than dead" battery condition.