I think 10 minutes is about the limit on a battery, maybe a little more. Search this forum because I remember people have revived dead batteries or sent them to someone to have them revived. Good luck!
Are you connecting the controller to your phone via Bluetooth or cable? Are you on airplane mode on the phone? I use a cable and put the phone in airplane mode.
I'm in the same boat. My last flight was pre COVID, but I've kept the batteries charged every few months so I just need to get re-registered and up in the air.
Jerry