Caps lock key flashing when typing.

For a while now my caps lock key has been flashing while I type. And yes I turned it on but when I type it just flashes but when I stop typing and caps lock is still on it is perfectly fine. Its very random and I read that means my battery is funny so I hope it isn't.

My battery is at 736 Cycles last 3-4hrs on full charge :( and its battery health is 78% (except that is from the app battery monitor since my Mac doesn't support Catalina)

Device is: MBP Early 2011, 2.3 GHz Intel Core i5 Dual Core, 8 GB 1333 MHz DDR3, 480GB SSD, Intel HD Graphics 3000 512 MB. And it running its max os which is 10.13.6 High Sierra.