The shore power converter doesn't give you enough amps to lift that roof. I had this happen on my old pop-up. When it started lugging going up, I knew to check the battery.
Your battery still needs to be halfway decent to lift the top. In a pinch, borrow the good one from your car (or some other 12-volt vehicle). Disconnect the Rockwood battery, hook up your car battery. Once it is up, disconnect the car battery and hook back up your Rockwood battery (reinstall the battery in your car).
You really need to replace your battery.
Ben and Doreen
Home Away From Home - 2017 PT Crusader 315RST
TV - 2008 F250 Lariat SuperCrew 4X4 6.4 Diesel
Never Enough Time Camping!!