u/Full_Bat3145

I purchased this Kindle at Goodwill for six dollars. It had this message on it at the time. I bought a replacement battery on Amazon and installed it. It will charge, but it doesn’t hold a charge for very long(3 days) Does anyone have any suggestions? What might be wrong with it or if I should even bother with it? I have a Kindle color soft, but I just liked the look of this one and thought it would be fun to have another. Oh, and it has not been de-registered from the previous user. I was thinking about jailbreaking it, but really I’m just looking for any advice.