The Battery Backup Sump Pump is a completely redundant system and work independently of your main sump pump. These types of systems come in main forms but the best provide the capability to monitor the pump and the battery condition. They can also run from the main power when it is available.
When you buy a battery backup sump pump make sure that you by a system that has the same capacity as your main system. It should also provide a alarm and to notify you if it is in use or if the battery is going bad. Not much use in having a backup if it doesn’t work when you need it.
The battery backup sump pump system is really the best choose for your home.

Below is an image of what a typical set up might look like.