Crystal, as you say your data array is defined as g_vArrayVol[4][32]
I have stressed out the dimensions since your problem is directly involved with them: when you are printing out the battery voltage, you are passing to sprintf g_vArrayVol[i], thet is the address of the whole 32 elements array of index [i] (let is to say, the whole i-th row in the matrix); the error you are finding states exactly that the parameter passed to sprintf is an array (i.e. a pointer to a memory area that stores actual data in double format) and not a double precision variable.
You should instead pass an individual element in the 2d array, as an example g_vArrayVol[i][0] .