Battery life was way to short even in standby with no use.

My Problem

To hopefully get new life on my 4s with a NOS battery from ifixit.

My Fix

15-20 minutes.

My Advice

Tweezers or hemostats, magnifying glass (lighted standalone type if possible), a white towel or the like to catch the screws and the grounding clip when they fall(and they will), and lots of bright light.

I forgot to use eveyones advise to wear gloves to keep oil off the contacts, but so far it's working fine.