Car audio systems use the most reliable type of rechargeable battery the 12V 18AH valve regulated lead acid battery. Chrome Battery offers a large inventory of BlockShakers High Performance Power Cells to replace your existing battery. Absorbent Glass Mat (AGM) Sealed Lead Acid batteries are considered the highest performing battery available on the market today. Each BlockShakers 12V 18AH Car Audio Battery is maintenance free and fully charged. BlockShakers is constructed with lead calcium alloy and absorbed glass mat technology, which allows a completely 'maintenance-free' operation. BlockShakers are sealed lead acid, no spills or leaks and will provide extreme vibration resistance for all that pumping bass! No Spills, No Leaks, No water to check, AGM Separators for superior design, Heavy Duty Terminals, Extreme Vibration Resistance, Improved Life Cycle Performance, Supplied Factory Activated (Filled, Sealed, Charged) for immediate use All BlockShakers 12V 18AH AGM car stereo batteries are manufactured with the highest quality materials and rigorously tested to ensure safety, OEM compatibility, effectiveness and optimal performance.Top notch Customer Service and Satisfaction is our top priority at Chrome Battery. Thank you for choosing Chrome Battery for your BlockShakers 12V 18AH car audio battery purchase your business is greatly appreciated.