2009 Macbook only holding 21% charge suddenly?
So I use Coconut Battery, and when I checked on my battery a month and a half or so ago, it had 79% maximum charge; not bad for a 3.25 year old laptop.
But when I checked it again today, it was suddenly at 21% max charge??
What did I do? Can I do anything to reverse this, besides buying a new battery?
MacBook, Mac OS X (10.7.4)