I cant help you here with the ct4850 (although I have its sister, the cordless drill, and the batteries last a long time), but just a bit of message board advice. Not everyone reads every thread, so a title like "run time" describes very little of the info you want, to a possible poster. I actually passed over the thread several times before getting bored of not seeing anything new, so I read it.
Suppose the thread read:
"Expected run time of the Snap On CT4850 battery charge"
That way, anyone that could have info to help, will see exactly what the thread is about, and therefore have a better chance of that person opening the thread, and not just passing it over.