Most homes with finished basements have a back up sump pump in case the primary sump pump fails. Once the decision is made that a backup sump pump is needed you will need to decide what type of sump pump you want. There are two different types of sump pumps available battery or water powered. You need to decide on the place where you want to put your new back up sump pump. If you are going to go with a battery-operated unit it is best to install it above floor level, water on the floor could damage the unit.
Because of the water needed to operate them water sump pumps are more expensive to run. Before getting started make sure, the area where you will be working is clean and dry. While purchasing the sump pump you will also need to purchase a rechargeable 12-volt battery, a good long-term investment would be a marine deep cycle battery they are more expensive but they will run for a longer period, and their shelf life is longer when unused. When you purchase the sump pump a water level sensor, needed piping, and a check valve should be included. The check valve is usually placed in front of the pipes to prevent a back flow into the primary pump when the backup pump is being used. You need to purchase PVC suction pipe, plastic of copper piping, discharge pipe, and a plumbing kit (if needed).
For a water powered model, the mounting must be positioned over the main sump pump. You will need to connect the water supply to the new pump. If you are installing a battery powered model make, sure it is fully charged then connects it near the main pump then connects it to the discharge pipe. With the water powered sump pump an extra step is needed yo,u must attach plastic or copper piping from the backup sump pump to your water supply. Regardless of which type you install the rest if the instructions remain the same for both types of units. Add the PVC suction pipe running it to the bottom of the sump pit, emptying the entire pit. Finally hook up the discharge pipe to the primary discharge or to the outside.
Testing once a month is recommended to assure the backup pump will work when needed. A good time to test your back up system is after a rainstorm. The main sump pump will need to be temporarily disconnected from its power source to the backup system. A battery charger with a trickle charge can be used to monitor and test the battery making sure it has adequate fluid on the inside and is retaining a full charge.
Strategically placing a battery powered water alarm a few inches below the top of the sump well can alert you with a loud shrill alarm if the pumping system fails and the water level rises too high alerting you of a potential problem.