i say try the alternator first chances are if it starts up fine yur battery is good

alternators cause what yurs is doing 9 times out of 10

my dsm used to turn EVERYTHING on like a last burst of energy when the alternator died.

i mean lights wipers battery door ajar coolant oil EVERYTHING would come on. change out the alternator.

BTW WTF is in yur hatch HAHAHAHA