These are the new generation, dual container, deep cycle Rolls batteries from Surrette. (S-460 and S-530 are not dual container). They are high-capacity batteries with heavy duty plate grid to resist positive plate breakdown. The plates are double insulated with glass mat and a polyethylene envelope, eliminating the possibility of separator misalignment, cracked separators, treeing or shorting at the bottoms or sides. Rolls batteries are rated at 3200 cycles at 50% depth of discharge except for S-460 and S-530 which are rated at 1000 cycles. Each 2-volt cell is built into its own lightweight container made of durable polypropylene with the cover heat bonded to the container, thus acid leakage is eliminated. The cells are then assembled into a tough, lightweight polyethylene outer container with a removable lid. Even if the outer container were to break, the battery would still be operable without acid spills. The individual cells are bolted together (CS and KS series) allowing the battery to be disassembled and the cells can be independently removed. This facilitates easy on-site installation, disassembly, assembly, or replacements of individual cells without special skills or tools. All Surrette CS & KS deep cycle solar batteries come with a 10-year warranty, 3-year full warranty, and 7-year prorated. Free or discounted freight may be available. Call us for a shipping quote.