Sump pumps are one of the most boring parts of home ownership. Until that one storm comes and suddenly they’re interesting.
After losing power one time this summer, I got paranoid and decided to build a battery backup. Home Depot had the basement watchdog systems, but they seemed high maintenance and I wanted something that would let me be lazier. I went with a LifePo4 battery system, that will (hopefully) get me 10 to 15 years. The battery charger has a float/storage mode so it can stay on 24/7. Doing some test runs, I think I can get about 400 cycles out of the battery before it hits 0%. I added some additional safety features (DC circuit breaker, GFCI with auto-on, Lithium fire extinguiser, etc), and added some battery powered lights and a basket of hand tools, so in the event the power goes out in the dead of night, something goes wrong, and I have to get my feet wet, everything is there ready to go.
We got flooded a bunch of times when the power got knocked out, because the town allowed development onto old swamp land that became a flood plain when the lake level was high and heavy rains came.
My dad installed a water based pump, it had a turbo type spool. City water pressure coming in on one side spun the pump shaft to pump out the sump. You are dumping city water into the sump too, but at a small volume x high pressure vs pumping out at low pressure x high volume.
So all was fine, just had to hope the town didn’t lose water pressure at same time as power outage.