A SLA battery (search batteries plus homepage, each AH of battery life is roughly 1 hour of pump run time). A charger for said battery (same webpage, I would get the little .5amp trickle charger). A 6105.500 safety connector. Each pump will need a safety connector but these could share a battery and charger. Ideally the battery would be in a splash proof box, these are same type of batteries that are in most UPS systems and in your household alarm or a childs power wheels, they are quite safe, but electricity and salt water is never a good mix. You will need some wire and slide terminals, most batteries plus stores are pretty helpful so if you bring them the safety connector they should be able to get you the right connections for the battery you choose.