Controller not charging

Hey there, I’ve had a DJI Air S2 for a few years. Last time I used it (about 6 months ago) it worked fine. Today I plugged the controller in to charge it. The four lights blinked on and off (like in a normal charging session) for about five minutes but then stopped completely. When I push the On button twice the lights momentarily light up, but then go dead. Anyone have any suggestions about how to fix this or what is going on? Any help would be appreciated. Thanks in advance, Scott