Maintenance free - no need to add battery fluid or distilled water Compatible with all new PHCC Pro Series backup products Up to 50 hours of protection (based on a 10% duty cycle) on the PS-C33 combination and PHCC-2400 battery backup sump pump system Up to 60 hours of protection (based on a 10% duty cycle) on the PS-C22 combination and PHCC-1730 battery backup sump pump system Up to 100 hours of protection (based on a 10% duty cycle) on the PS-C11 combination and PHCC-1000 battery backup sump pump system Runs pump intermittently for days