Toys "R" Us discounts select packs of alkaline batteries. Even better, buy one pack and get a second pack of equal or lesser value for free. With prices starting at $4.99, that's tied with our early January mention as the best discount we've seen on these items from Toys "R" Us. Opt for free in-store pickup to avoid the shipping fee of around $6. Sales tax is added where applicable. Choose from AA (20-pack pictured), AAA, C, D, or 9-volt.