The Protech 80901006 Battery Pack is the factory-specified replacement battery for SOLARIS and PORTALIS solar-powered infrared barrier towers. Rated at 4V, 5Ah, this rechargeable battery pack provides reliable backup power to maintain continuous perimeter protection during extended periods of low sunlight or overnight operation. Designed for easy field replacement, the battery slides into the tower's integrated battery compartment, minimizing downtime and maintenance costs. Compatible with all SOLARIS towers and PORTALIS gate barrier towers, this essential accessory ensures your wireless infrared perimeter remains operational around the clock.