Is that the original battery in your Nitro? They really only last about 3 years. If so put that on your to-do list. Not sure it would cause your issues however. Head replacement is not normal for a Nitro.
Nitro Year: 2007 (1 of 91,815 sold in 07)
Nitro Model: R/T 4X4 Stone White
CAT-BACK Exhaust, CAI, Projector Head Lamps
Fully-Equipped w/all factory options