If you have charged it overnight and still don't get results you can consider getting a replacement battery from Newpower99. Here's a link to their page for that Kindle:
https://www.newpower99.com/ProductDetails.asp?ProductCode=Kindle%203%20with%20Special%20Offers&gclid=CjwKCAiA6aSABhApEiwA6Cbm_xBHaKW0921dNtpp8ItFy9ZIQ3HbCYL2nylrEue-A8b3P_LY3bxkTBoCDwAQAvD_BwE
It includes a video showing just how to replace it which might help you decide if you want to do that. Keep in mind that you can get that same model Kindle from Ebay for about the same price or maybe even less.
You can also get batteries from Ebay for much less but I don't recommend that. I replaced the battery in a Paperwhite a couple of years ago and I bought a battery from Ebay for about half what the Newpower99 battery cost and it wasn't much better than the old battery. It is a LOT of trouble to replace these so if you're going to do it I strongly suggest a battery from a reliable source. I've never bought a battery from Newpower99 but they've been around for decades and they have a very good reputation. I wouldn't make the same dumb mistake I made.
Personally I don't think this thing is worth the effort. I'd get a replacement if you really want an older Kindle like this, or get a newer model, which are much nicer. After replacing the battery in my Paperwhite and learning just how difficult it is to do I don't think I'd do it again and that would be true even if the battery I'd used had been a good one. And the Paperwhite is a much nicer Kindle.
Barry