2011 MBPs (15" 8,2 and 17" 8,3). Batteries run for about ~4.5 hours before conking out. Have already pulled the trigger on NewerTech NuPower batteries (along with 16GB RAM and 1TB SSD for each) and hoping to get a couple more hours back, or at the very least similar run times while using the 17" as a Windows Server 2016 install and the 15" running Windows 10, both with Hyper-V enabled to use as portable labs. When did you decide enough was enough and you had your machine's battery replaced? Any recommendations on safely storing either new or old batteries for an extended period in the event I want to use them at a later date?