If your cycle count is 223 and you are nearing 80%, then your battery is defective, plain and simple. Apple will replace it. It's happened to me a couple times and Apple took care of it with no hassles.
First time it happened (and was still under warrantee), I took it into Apple, and they said it was normal, and they only replaced batteries if it was defective.
I went through 5 batteries until I got a 2011 MacBook Pro.
Back then the batteries were only rated for 300 cycles so if you were above that they wouldn’t exchange it. Apple did exchange the battery in my MacBook Pro (2007) three or four times or so (I had Apple Care, so warranty for three years) because I had similar problems you had – but each time my battery was below 300 cycles. As far as I know that is official Apple policy. I never had to convince or smooth talk anyone, they just exchanged in, no questions asked. And I didn’t exchange the battery always in the same place, once or twice over telephone, at an Apple Authorised Service Provider, at an Apple Store.
Is this replacement worthy? What am I doing wrong?
730 cycles, 92% capacity after 27 months (mid-2011).I actually thought this perfectly reasonable, with nearly 4 years being a fair lifespan for a battery, no matter how few cycles it might have been through. While it was obviously knackered, it still held enough charge to be perfectly useful, if not amazing - but perhaps I should have held it to a higher standard?
(Hopefully it's just this year's unusually hot UK summer but after a mere ten cycles its replacement is down to 93% already. So maybe there's just something up with the electricity supply to my flat.)