As far as set up for the pumps. I have two 3/4HP pumps. One stacked 2" higher than the other. Both have their own check valves. Wyed above the valves to a single line. THEN, I split the lines in two. Another wye. Ball valves on each wye. 1 line runs to the front road ditch, always open. The other line (alwasy closed) runs to the back of the house to a valve box and I have a banjo fitting so I can hook up a lay-flat line. I've used it to assist in filling a pool (who mentioned that?). The sump was cast into the concrete floor. The hole size is 24" square and about 16 inches deep. Each line has a union fitting so I can swap out the pump in a hurry without cutting pipe. As mentioned before, no battery back up. Seems pointless, but I've never ran the calcs. I'm guessing I'd get about an hour out of each battery. Maybe 2 max. Emergency generator has been used a half dozen times to prevent flooding. Natural gas, so no worry about refilling tank. Just have to be here when it's needed. Standby genset would be ideal, but cost is high. It's in the "wish list". I've learned that during normal times, I have almost exactly 2 hours before the water breaches the top of the sump. The pump runs for a good long time when this happens. The footprint of the basement is about 1600ftsq and around 330 linear ft. I can only assume that the whole area below the floor is getting saturated during these times.
Most of the time when the power goes out here, it is back on before that 2 hour window. I guess I must be pretty lucky/good with it as I've never had a flood b/c of power loss.
I swap pump positions on occasion to make sure they are both used. I keep an additional pump on hand, but since doing so, have never had the need to use it.