new battery install "service battery" deep sleep not working

alright I just replaced my old battery in a late 2011 15" MBP (I got one online)

everything was fine, I turned it on and it said battery was normal so I charged it up full for 2 hours then unpluged the power lead for it to drain to recalibrate the battery so it got down to about 8% then a warning came up saying it will turn off so I was under the impression that by default it would go into a deep sleep and decharge the battery down to 0% over the next 5 hours but what happened was the MBP was just turning off.

so I did that 2 times as I saw something was not right as when starting the MBP it was still at about 8% then the error came up saying "service battery"

I thought that when a MBP is not plugged in and that battery dies it goes into the deep sleep mode for many hours and you can plug in the power plug when it's in sleep mode and it will awake.. is this right?

any help would be great, thanks! 🙂