PS4 Controller-Batteries no longer charge. Replacement help?

Both of my PS4 controllers refuse to hold a charge; warranty is expired. Should I replace the batteries? What replacement battery should I purchase? How can I avoid this in the future? What cord should I get or how should I charge them from now on?

I'm hoping this isn't considered a "low quality question" and I would like to actually talk to others about this issue I'm having.

Any advice helps, if I am in the wrong place please let me know.

Edit: This happened quite suddenly, both stopped working within days of each other, like 2-3 days. The controller that came with the PS4 no longer lights up and will work for a few minutes before dying. The second one that was bought about a year ago doesn't hold a charge either but still lights up.