VMAX V30-800 12 Volt 30Ah AGM Deep Cycle SLA VRLA Battery for Marine RV Golf Solar, High Performance Batteries ideal for boats and 18-30lb minn kota, minnkota, cobra, sevylor and other trolling motors 6.5"*5"*6.9"H Heavy Duty 12V 30Ah AGM DEEP CYCLE BATTERY with Float Service Life span of 5 to 8 years. Electrolyte Suspension system VMAX tanks utilize an electrolyte suspension system consisting AGM (Absorbed Glass Matt) of a high porosity that totally absorb and contain the electrolyte. No silica gels or any other contaminants are used Heavy Duty Grids: VMAX heavy duty lead tin alloys provide an extra margin of performance and service life in either float or cyclic applications, even after repeated over discharges. Maintenance Free Operation: There is no need to check specific gravity of the electrolyte or add water to VMAX tanks during float service life. In fact, there is no provision for this type of maintenance. Visit Manufacturer's web site for further info vmaxtanks.com