sump pump battery back up

Ed jr.

I currently have a sump pump installed already, What I would like to know is if I can buy a battery back up system without having to replace my existing sump pump. All the systems i have been able to find, you have to change out the existing pump for their new one............Is it not possible to keep existing one and just hook it up to the battery???? Are battery back ups dependable????
Thanks any info would be greatly appreciated!

Daniel Holzman

A battery is DC current versus the AC current coming out of your wall. A typical battery backup pump uses a DC motor which can run off the battery, and an AC-DC converter for house current. If the power goes off, the battery continues to supply current for as long as the battery is rated, which is typically 12 - 24 hours. So in this case, you need a DC powered pump.

An option is to have two pumps, one standard pump which runs off the AC current in your house, and a backup DC pump connected to a battery which is kept charged off the household current. When the AC power goes out, the system senses this, and switches to the battery backup pump. This type of arrangement requires two pumps, and of course a larger sump pit than a single pump system.

A third option, which I have not seen but may be available, would be to connect the battery through an inverter that converts DC battery power to AC power for the pump. This would allow you to use a single pump, but would require an expensive inverter. I have never seen this in a residential application, perhaps someone else has.

A final option, which is very good, is a water powered backup pump. This works if you are on city water, as the pump runs off municipal water pressure, which is likely to be unaffected by a local power failure. This requires two pumps as well, one AC pump, and a water powered pump.

Plumbing_Guy

Not really. The pumping capacity is much lower than 120V pumps.

They use a trickle charger which can lead you to think that the battery has lots of power. All batteries lose charging capacity over time. The unit may work for only 5 minutes before the battery is dead. You have no way to know how long the battery will last.

We stopped installing these type of units 2 years ago. We now only use NexPump products.