The float switch is what turns your sump pump on and off in response to the water level in the sump pit. It's like a beach ball that floats on top of the water. When the water rises, the float rises with it. When it gets high enough, a switch inside the float closes and turns on the pump, draining the pit.
https://www.plumbingsupply.com/sumpwatcher.html
Some homes with basements or crawl spaces are protected from ground water damage by a network of drainage tubes around the foundation. These direct water into a shallow pit, or sump, where a sump pump pushes the water out and away from the house through a discharge pipe.
https://www.lowes.com/projects/repair-and-maintain/backup-sump-pump-bg/project
The SumpWatcher does what the float switch does, only much, much better. The float switch hasn't changed much in the 75 to 80 years it's been used to control sump pumps. It is a mechanical device that has to eventually wear out.
https://www.plumbingsupply.com/sumpwatcher.html
Without battery backup during a power outage, your sump pump will stop working and your home will. be placed at risk. You could buy a battery backup system. from your plumber, but these proprietary systems are very. expensive to purchase, install and maintain.
https://www.tripplite.com/shared/literature/white-paper/how-to-select-inverter-for-sump-pump-white-paper.pdf
A battery backup system for a sump pump consists of two main components: an inverter/charger and one or more. batteries. The inverter is responsible for converting the power stored in the batteries into a form that can be. used by your sump pump.
https://www.tripplite.com/shared/literature/white-paper/how-to-select-inverter-for-sump-pump-white-paper.pdf
Types of Sump Pumps. · Submersible sump pumps are built with a special motor that is completely submerged in oil to provide a superior cooling and lifetime bearing lubrication. The sealed construction prevents dust and moisture from entering the motor and extends pump life.
http://www.flotecpump.com/residentialpage_resource_pumptype_SumpPump.aspx
Key Product Features: 1  Replaces most float switches. 2  Makes most manual pumps automatic. 3  Easy to set high-water level.  Low water level is computed 1  automatically. Fits in very narrow sump pits, where most floats are hard to 2  fit. Ideal for a second pump when space in the pit becomes very tight.  Installation is easy, requiring no tools.
https://www.plumbingsupply.com/sumpwatcher.html
Types of Sump Pumps. Most sump pumps are either a pedestal or submersible type. With a pedestal pump, the motor is on a shaft above the sump, out of the water. Generally, these are a less expensive option. Because they’re not cooled by the water in the sump, however, there’s greater risk they’ll overheat under extreme use.
https://www.lowes.com/projects/repair-and-maintain/backup-sump-pump-bg/project
Selecting and Installing a. Battery Backup System. for Your Sump Pump. Executive Summary. Your sump pump is your home’s first line of defense. against flooding, but what happens when the power goes.
https://www.tripplite.com/shared/literature/white-paper/how-to-select-inverter-for-sump-pump-white-paper.pdf
Sump pumps are automatic pumps used for sump basin drainage or in emergency situations. The most common application is for basement drainage to prevent residential flooding. · Submersible sump pumps are built with a special motor that is completely submerged in oil to provide a superior cooling and lifetime bearing lubrication. The sealed construction prevents dust and moisture from entering the motor and extends pump life.
http://www.flotecpump.com/residentialpage_resource_pumptype_SumpPump.aspx
what is an automatic sump pump
Sump pumps are automatic pumps used for sump basin drainage or in emergency situations. An automatic sump pump is  pump used for sump basin drainage or in emergency situations.