Battery Backup Sump Pump vs Only a Sump Pump
A backup on its own is useless, because it does not have the power to work alone. When used in addition to a sump pump, it provides maximum insurance for your basement.
Another consideration when deciding whether you need a battery backup is the presence of a generator in your home. A generator will help with power outages, but it will not be very useful if your sump pump fails due to age. It also will not assist with giving your sump pump an extra boost if the pump begins to get overwhelmed. A battery backup is also the more affordable option of the two.
In a flat, very wet area, most homeowners take precautions against flooding with sump pump and battery backup sump pumps.