One quick implementation for the Python script to run every 15 minutes is to use an infinite loop with 'While'. Instead of relying on a batch file, you can have your python script wait 15 minutes before running again.
import os, time, sys, datetime
while True: # Use WHILE = True for an infinite loop
timestamp = datetime.datetime.now()
print('''
RUNNING PYTHON SCRIPT EVERY 15 MINUTES
PYTHON SCRIPT INITIATED AT %s
''' % timestamp)
# ENTER PYTHON SCRIPT HERE
print('''
PYTHON SCRIPT COMPLETED AT %s
''' % timestamp)
time.sleep(900) # 900 seconds = 15 minutes before next run