 Hi, I'm Tom Scherer, agricultural engineer with North Dakota State University Extension Service. Today we're talking about electric backup sump pumps for houses. Since the battery provides all the power for the backup sump pump, it's important to check it periodically. I would recommend about every six months. In this part of the world, we get snowmelt, so the early part mid-March would be a good time to check your backup sump pump to make sure the battery is in good shape. The other time might be after first killing frost. If we get fall rains, a lot of times we can get a lot of flow into our basements because there's no plants using the water. So you want to check the battery, so in this case we've got it connected to the charger and we have a relatively inexpensive voltmeter here and what we want to do is just check the voltage and in this case you see it's reading around 14, that would be, that's with the charger on. We can unplug the charger and then just check the voltage, then you see it's about 13.7 which is a very acceptable range. You want it well above 12.7 when it's sitting there with no load on it. But the other important measurement you have to make is when there's an actual load on it because even though the battery reads the correct voltage, when you put a load on and start drawing current it may actually be quite a bit lower. The charger is unplugged and now we're going to put a load on it. We're putting water into the sump and we'll measure the voltage under load so that we can see if the battery voltage stays fairly constant and doesn't drop too much when it starts to pump. So you can hear the sump pump turned on, it's running, it's pumping water, it's dropped to about 12.7, that's very good and that's what you would want. If it drops down to 11.5 then your battery might be getting weaker or older and it might be time to consider replacing it. One of the questions we get asked a lot is how much actual protection will your backup sump pump provide, such as battery powered. We set up a test stand in the lab here and we set it up just like you would from a normal house with a full basement and we measured the amp draw on the pump and we found on this particular DC pump it draws about 10 amps. So we tested it with this 40 amp hour battery under continuous pumping. Now that's the worst case scenario, you've got so much water coming in that the pump is just running continuously. This provided about three and a half hours before the battery ran out. This 75 amp hour battery provided about six and three quarter hours of protection. So if you take 75 divided by 10 you get seven and a half hours, it's a little less than what the rating is with this motor. This one is an 84 amp hour battery and it provided about seven and a half hours of protection. Now if you had a bigger battery that had about 120 amp hour of protection, that would have provided about 11 hours of continuous pumping. But most of the time some pumps don't pump continuously so the second test we did was we set it up so that the pump only ran once every four minutes, which is still quite a frequent pumping interval. And the smaller battery here, the 40 amp hour provided about 32 hours with the pump running every four minutes for about 15 seconds. The battery is actually able to recover a little bit between times. The 75 provided about 60 hours of protection, or about two and a half days or so of this intermittent pumping. And this one provided about 68 hours. So it's almost three days. Now if you bought the 120 amp hour battery, that would provide about 96 hours or almost four days worth of intermittent pumping before the battery would go out on you. So in an emergency situation, if your battery is going low and you've been out that long and it's pumping quite a bit, you can always go out to a vehicle in an emergency situation. You could substitute in a 12 volt battery out of a riding motor or out of a boat or pickup or a car to give you that extra protection you need. I'm Ken Helibang, agricultural engineer with the NDSU Extension Service. Tom went through things in our lab relating to the backup sump pump. Now we're in a home and we're going to actually look at an in-home installation. So here we have the sump that Tom was talking about. It's down below the floor level. We have our main sump pump at the bottom. In this case, rather than having the backup sump pump sitting beside the main sump, this installation has the sump with the battery power, the backup sump pump sitting a little bit higher than the primary sump. And then we also have the same check valve and connections that we saw in the laboratory. In this case, the power comes from this battery that's sitting in this protective case and frequently they will be in some type of case so that we're protecting the battery and we're protecting the floor in case there's any acids that come out of that battery. In the lab we saw the trickle charger was separate from the actual battery case. In this case here is the trickle charger and the way that this is installed, the line or electric line comes from the backup sump pump, comes into the trickle charger here and then in this case we have now the switch that goes back down and is adjusted so that the float is higher than that primary sump. So if the primary sump would fail, then that switch would lift and activate and turn on the backup sump pump. The power is coming from the battery that is in this case and we'll just lift off the lid so that we can see here the battery sitting in this case. This is a deep cycle battery, marine type that we discussed previously that has the pulse where the power comes from the battery to operate that backup sump pump and then the trickle charger has another cord that goes over and is plugged into the wall and we're constantly trickle charging the battery. So it's important as Tom was indicating for us to verify that that whole system is operating, check the water level in the battery, check the sump to make sure that that backup sump pump switch does turn the pump on, make sure that we're keeping the charge adequate and in this case they have a light readout that will indicate the level of charge. So this will then provide some backup protection for the home in case the primary sump pump fails or if the power goes out that this electric DC powered backup system will then start operating and keep your basement and home dry.