The OTR Group Size 31S Silver Heavy Duty Truck Battery ensures Expertise Built In™ is built for power from the inside out, featuring state-of-the-art grids that are calcium/lead alloy punched. This technology provides maintenance-free performance, consistent power, enhanced durability, and added cold performance for increased starting capabilities in colder temperatures. Our Silver Group 31 batteries are great OEM replacement batteries to keep you moving down the road. OTR knows what it takes to repair and maintain Class 6-8 trucks, so they deliver solutions, making your job easier and more efficient. OTR warranties are comparable to or better than OE and top brands. All heavy duty truck replacement parts offer the same form, function, and fit as the OE replacement parts. FleetPride is your First Click in Heavy Duty®.