The Basement Watchdog Big Combo is a pre-assembled energy-efficient 1/2 HP primary sump pump combined with the number one selling Basement Watchdog Special CONNECT Battery Backup Sump Pump System. It s the D.I.Y. solution for replacing your current sump pump with an efficient cost-saving one that includes a redundant battery backup system with 24 hour a day monitoring and a Wifi capable controller. With two sump pumps in your sump pit continuous monitoring and remote notification capabilities allowing you to receive texts emails and in App alerts you can feel safe that your basement is protected. The system is easy to install with little or no plumbing knowledge required. The ? HP Cast Iron primary pump provides outstanding capacity-pumping up to 4 400 GPH at 0 ft. lift. The backup sump pump is battery-operated and pumps at 2 600 GPH at 0 ft. lift. The backup sump pump can run intermittently for days on a single battery charge from either the Basement Watchdog Maintenance-free AGM battery (BW27AGM) o