My Ipad Mini 2nd generation has died.

As far as age goes, the 2nd gen Mini uses an A7. It's still relatively modern, but we're up to the A12/A12X/A12X Bionic/A12Z at the same time. As frustrating it is, you don’t spend a lot of money on it unless you have a 64-128GB model. The 16/32 variants are just too common to spend hours fixing in many cases :/.

However, if you are happy with it you can replace the battery and it will be good to go again. However, it is not an easy repair to get done. Take your time or have a shop do it if you aren’t comfortable.

Refer to this guide to change the battery. The part is $44.99 in a fix kit here, and $34.99 for just the battery. To get an idea of the cost of a new one vs. a new battery, shop around for a similar capacity 2nd gen or better to get an idea of what you want to do. Common capacity (16/32GB) Minis tend to be cheap, but the 64-128GB hold their value to the point it may make sense to replace the battery.