It seems that people have been looking for the perfect, fool proof sump pump system ever since the technology was originally developed. Each type of pump and its backup pump seem to have inherent weak points. Of course any pump on its own without a backup system is a recipe for disaster, so the best that you can do is try to decide what best suits your current situation.
Is there a Fool Proof System?
On the surface, a battery powered backup system would appear to be fool proof. However; if it was as it appeared, wouldn't the battery powered pump be the main sump pump? The reason for this is that even a battery powered backup sump pump has its down side.
Water and Electrical Powered Main Pumps
Its not hard to figure out how a sump pump and its backup system work together. If the main sump pump fails, then the backup system will kick in and do the work of pumping the water out of the basement. There are two main sources for power that a main pump will be run off of and they are water or electricity.
Battery Power is Reliable
A battery powered backup sump pump is designed to kick in if either one of those two types of main pumps fail. The electrical main pump can fail if the power is shut off and the water powered system can fail if it is overwhelmend by a deluge of water that it can't handle.
Batteries Last Only So Long
Battery powered sump pumps work great but they have one big weak spot. That is that the battery's can run low and then the pump will fail. But cant enuough batteries be stored? Even then if a storm system goes on for a week and there is no power for the entire duration it is simply impossible to have enough batteries.
Creative Engineering is the Answer
So what is the solution? There is no fool proof sump pump system that will go on indefinitly. This means that you can have a reliable system with a battery powered backup sump pump but it will only last so many days