Battery boxes are used to secure the batteries on a boat against the extreme movement of the craft on water - a marine industry standard and a Coast Guard rule. While batteries may sometimes be mounted on trays, they are more often stored and held in marine electrical battery boxes, which, besides keeping the battery in place, also protects it from exposure to outside elements like moisture while also containing the corrosive acids of the battery. Battery boxes also make moving and transporting the battery safe and easy. Battery boxes normally include a box with molded handles, a lid, a strap to hold down the lid and mounting hardware. Battery boxes are available from several marine manufacturers, although the most well-known are built by Attwood Marine.