Amazon.com has the 12-Pack AmazonBasics C Cell Alkaline Batteries for $7.79 when you clip the 30% off coupon and check out via Subscribe & Save. Shipping is free with Prime.

• A 24 Pack is $20 – 30% off coupon – 5% off with Subscribe & Save = $13. Shipping is free with Prime.
• 8-Pack AmazonBasics 9V Everyday Alkaline Battery for $10.99 – 30% off coupon – 5% off w/ S&S = $7.14 with free shipping on $25+ or with Prime