WAYNE ESP25n - 12 Volt Battery Back Up Sump Pump, Battery Not Included - Up to 2,700 Gallons Per Hour - Heavy Duty Basement Sump Pump

Easy to setup, wire-up, and get into place. Was a little-bit of a tight fit with both pumps in my pit, but they fit together facing opposite directions. These pumps are quiet, fast, and after 3 months, reliable. Battery backup has been tested a few times manually, and still seems to work well. I'm very comfortable with the setup. It took about 20-30 minutes total to setup with a Y-joint pipe and check valve cutting a new pipe to join the two, and I zip-tied the float to the pipe and tested with a water pour to be sure it wouldn't snag or hesitate. The battery I used was Casil 100 AH Deep Cycle AGM CA121000 SLA Solar/RV battery for $185, which got top ratings and matched the terminal requirements. I Mated this kit to a Wayne CDU980E 3/4 HP pump using the PumpSpy Dual Pump Install Kit and a Raybend,"Silent" Sump Pump Check Valve, 1-1/2" that I had installed prior to hooking up the backup pump kit. Altogether, I spent about $820-$850, which is much less than the $1800 I was priced for a 1/2, 1/3 HP kit by a local plumber. Between the two pump installs, drilling and mods, and running 3 more drain lines that were never installed originally (Heater, tank, A/C condensation, and Humidifier) it took me about 60-70 minutes for all of the work, testing, and cable dressing. At $860 - $1000/hr for after-tax labor, it was well-worth my time, and surprisingly very easy to do. I may add pics later, if I have the time.Don't bother with the unsealed batteries, and the Li-ion's aren't worth the price, especially, as they cold pose a fire hazard in the humid environment you'll be using them in - unless you know the maker well and can trust the quality of the sealed system - especially since this charging system doesn't have the electronics to protect against surges or overcharging of Li-ion batteries. This system shouldn't go through enough cycles to make it worthwhile anyway. In fact, with the reliable power I have at my house, I really only need a standard 12V car or lawn-tractor battery, but it's worth the comfort of knowing this will last and have the capacity if the power goes out for awhile.

Our basement must have been built in the path of an underground stream. After a big rain, water will continue to come into the sump for several days after the end of the rain. Basement flooding is a certainty if the sump pump isn't working. So AC power, or no AC power the sump pump must continue to run!The AC-powered pump component is typical of good quality flooded pumps, powerful and quiet. But it is the DC-powered backup pump that sets this unit apart. We've had other DC-powered backup pumps, but they typically fell short. We have about a 7-foot lift between the top of the sump and the ground surface where the water is discharged. The other backup pumps would run, but strain to remove the water. Not so this pump. The backup pump design is very similar to the primary AC-powered pump and takes only about 30 seconds to empty an 18" round 30" deep sump against that 7-foot (minimum) head. In a recent test following a 4" rainfall event, the backup pump was needing to empty the sump about every 3 minutes during the peak drainage. It ran on battery power (admittedly off a 100-amp-hour AGM battery) all day and through the night without any visible drop in the battery voltage until there was no more water to be pumped.With one caveat, installation is easy, primarily because the plumbing interconnecting the two pump units is built-in. The caveat is that the base of the unit is massive, with the two pumps mounted side-by-side (instead of vertically as many of the lighter-duty units are). We have an 18" circular sump and it just barely fit - in part because while 18" was ample for the center of the unit, the corners just barely fit.We did make one alteration. We are charging our battery using a high quality, stand-alone charger. Why? The main limitation on battery life is likely to be how it is charged (or, if things don't go right, overcharged). The built-in charger may be OK, but given the cost of the battery, we thought investment in a computerized low-amperage charger was a reasonable one. The good news is that the pump control electronics built into the battery box work fine with the AC charger cable detached. The charger type makes no difference when the backup sump pump is actually running, because, by definition, the AC power will be off at that point anyway.Given its solid design and construction, and that it seems to do the needed pumping with little evidence of effort, I'm expecting this unit to keep us dry for many years .