Aura Battery issue and questions

[christopher22]

There are a few questions within this thread.

How long should a battery stay close to 100%?

I fully charged up my kobo to 100%, then turned it off. In the morning when I turned it on it read 79% ?? When I plugged it in to charge, it immediately went to 90% and charged to 100% in about 5 minutes. Maybe the charging is fast on these things I don't know how long it's supposed to take to charge up. I've charged it up a few times so far. Maybe it needs a few more charges? but it doesn't take very long to drop to 90%. I do have until Jan 5th to exchange it.

Also what if when sometime in the future I need to replace the battery, how long do the batteries in these things last? Do I have to send it in to replace or can I replace it myself?