When the system is plugged in, it says "AC power wattage and type cannot be determined. Battery may not charge. System will adjust the performance to match the power available. Please connect a Dell 45W AC adapter or greater for the best system performance
Then it will move to a black screen.
I unplug and plug back in again and I get the homescreen.
After 15 minutes plus of booting back up, system performance will be extremely slow. Hard to type or call up any application
As a separate symptom, when I power up with the battery in, a message displays:
When I have the battery in, I get a message, "Your battery is temporarily disabled. Please turn off computer and try again when the unit back to operational temperature."
A double failure of the battery and AC adapter is statistically improbable -- however, the most likely suspect is also the most expensive one to replace -- the mainboard. You might try bringing the system to a repair shop (or even Best Buy) to see if another Dell adapter solves at least that part of the issue. If it doesn't, it's likely a bad mainboard.