Macbook Pro Service battery warning.

I have a mid 2010, 15inch, Macbook Pro. Just a few days ago I received the service battery warning and due to it my battery life has reduced by quite a bit. I am only able to use it for about 3 hours before I'm required to charge it back up again. Although my Macbook is quite old I'd like to eliminate all the other reasons before replacing its battery. I have tried resetting the SMC by shift+control+option keys and holding the power button but the warning still remained. I've tried recalibrating the battery and the warning did go away but just for few mins before returning. Using coconut battery I was surprised to see that the design capacity level had increased from 73% to 77%, so I might try the process again even if it is quite lengthy. I need helping getting rid of the warning and stopping the battery drain and would like to know all my possible options before needing to replace the battery.