Contrary to popular belief, compliance with ABYC Standards does not mandate that batteries be installed in boxes. In fact, unless they are of the flooded variety, I’d argue batteries are better off without boxes; eliminating them offers better ventilation and makes regular inspection far easier and thus far more likely. Once again, the standards state: “Provision shall be made to contain incidental leakage and spillage of electrolyte. Note: Consideration should be given to: 1. the type of battery installed (e.g., liquid electrolyte or immobilized electrolyte); 2. the boat in which the battery is installed (e.g., angles of heel for sailboats, and accelerations for powerboats).” It makes little sense, therefore, to install a gel or AGM battery in a box, since leakage is essentially impossible. Flooded batteries, of course, do benefit from 100 percent containment, since they are prone to leakage and occasionally explode.