Welcome to the Dell Community @Mess82 

Remove battery and locate label with the laptop power requirements.

It will look like 19.5V ~ ???A

Volts x Amps = Watts

Your AC adapter is 19.5V x 16.9A = 329.55W (330W)

Since you have a SMART power system your AC can always be larger than what the system requires.

Best regards,

U2

If that's the actual battery, it's nowhere near "new" -- it was made in 2014, making it about the same age as the system, or 7  years old.  

If it was sold to you as "new", I'd return it to the seller for a refund -- it isn't.

Most of precision M4800 with discrete graphics uses 180W power supply.