Cell Phone Charging Question--Phone About To Go Phhttt?

I have a cell phone which has given me really good service since 2005. It was dormant as was my wife’s, for almost 2 years while we were on Kwajalein.

Now, we are back in the states, and have reactivated the phones. They both work fine, except…when we plug hers into the charger, after the battery is nearly drained, it takes a while to recharge. Mine, on the other hand, will show a full charge in about 4 minutes. I “know” it can’t be recharged that quickly, and in the past, it did not recharge so quickly.

Same charger for both phones. Should I be concerned about mine dying in the near future? I have no issue with getting a new one, but this one works and I am used to it, and I don’t need any new/additonal functionality. But this concerns me.

Oh, by the way. As far as I can tell, I can talk for an hour or so no problem even if the bars are showing little to no charge remaining. I haven’t taken it yet to a full discharge so I don’t know if it holds a charge as long as it did; Just kinda weird.

Thaks for any advice.