I just replaced my 6 year old Sea-Volt group 31 house battery(West Marine(Exide)) with a Walmart Everstart MarineMaxx(Johnson Controls). The S.V. goes for $130.00 and the Everstart $65.00. All the important numbers are the same. I keep my house battery in the port-side compartment. Space is tight in there and a regular battery-box wastes space and the lid is unusable. Another way was discovered. Again at Walmart in their storage-container department is an item, Sterlite "Show-Off Box", $2.96. It fits snugly on a 31 and will contain any electrolyte that might escape in an overcharge situation. The Everstarts got mixed reviews in my research so this is something of a gamble(i.e., leaky cases). When I know more I'll report back.