how much does it cost to replace a battery backup for a sun pump
1 A separate battery-or water-powered backup emergency sump pump is $150-$350 or more, depending on horsepower, flow rate, materials and other features.2  A backup pump operates during a power outage or if the primary sump pump fails. An average sump pump (pedestal or submersible) for a typical home runs about $100-$300 depending on the horsepower, materials (plastic is less expensive than cast iron or stainless steel), flow rate and the height the water needs to be lifted to discharge it.