Update powerwall.sh

powerwall.sh

@@ -124,7 +124,7 @@ CHECKPOWER(){
 	
 	OUTPUTV2=`expr ${OUTPUTV%.*} / 2`
 	
-	echo "HERE $((${OUTPUTV}/2))"
+	echo "HERE $(($OUTPUTV/2))"
 	
 	echo "Input Power: ${INPUTV}V / ${INPUTA}A"
 	echo "Output Power: ${OUTPUTV}V (${OUTPUTV2}V) / ${OUTPUTA}A"