: How do I check to see if a sump pump is working? It is hooked up to a new battery and : recharger, however I havent heard it go on in awhile. Also how do I check to see if battery is : working properly? If I unplug the sump will the battery take over and turn it on or does it need : to have a certain water level? It sounds like you are on the wright track. Yes if you unplug the pump the back up supply sould take over, that is what it is for. To test it run water into the plumbing fixtures that drain into sump pump, thats it. if you do not hear the pump turn on you may have trouble. But it may take time to fill the tank . check it first with your regular power than unplug it to see if back up is working . Good luck