2008 dodge avenger with a dead battery, I am in the process of charging the battery now but while driving the transmission seemed to be stuck in second gear, the slap-stick would not engage either, is this related to the dead battery or should I be more concerned?

It is in "limp home mode." This happens when transmission errors occur, such as P-O700. You can try disconnecting the battery for 15 minutes, reconnecting it afterwards, and seeing if that clears the code and the problem. However, if it persists, the following may be informative: https://www.avengerforumz.com/threads/2008-avenger-p0700-p0760-stuck-in-1st-2nd.54831/

I'm not certain what SHUG means. Can you offer a better description?

It is normal for there to be a slight bump when shifting from park to drive, especially when very cold. Something I do that helps is to shift from park to neutral and wait a few seconds before shifting to drive. That seems to ease the process of shifting to drive. Also, check the fluid when the engine is warm and idling in Park. If low, add only the necessary amount.

have a load test done on the battery to check battery cell condition. If the battery is 10.5 volts after running then have the alternator bench tested for correct operation as it may not be charging

Clutch pack in the transmission went out, most likely. If so you will have to rebuild ****** or get a used one

My engine rattled and i had the same things done, the oil change and tune up because i had 83000 miles. That didn't fix the problem and after spending $120 the mechanic said it was the alternator because there was some build up on the side of it which he said is a way to figure out if its going bad or not. Anyway this cost me almost $700 to fix now the rattling noise is gone and all is good. The mechanic said that it was ok to continue driving the car but if the alternator went completely out be prepaid to have it towed once your battery charge is gone.
Just a 2008 Dodge Avenger owner for over 3years now.

EASIER TO RUN AN EXTENSION CORD WITH A BATTERY CHARGER INTO THE GARAGE!

Call AAA or CAA and get em to use a slim jim to open door, probably cost $50

Make sure you have your foot on the brake

check the sparking plugs

sounds like the brake shift interlock solenoid