What is a home battery?

Installers hang them in a garage, a utility room, or on a shaded exterior wall, because cells prefer roughly the same 32 to 90 degree range people do and lose both range and lifespan outside it. A battery does not simply plug into the house either. It needs a transfer switch or backup gateway that isolates the home from the grid during an outage, plus a critical-loads subpanel where the breakers for the fridge, well pump, furnace fan, lights, and internet get moved. Argue about that subpanel list before install day, since changing it later means an electrician and another permit.

Three jobs, and most systems do all three. Backup: keep the house alive when the line goes down. Arbitrage: charge at 12 cents overnight and discharge at 45 cents during a summer peak. Self-consumption: hold solar production instead of exporting it for pennies. A single 13 kWh unit typically carries a refrigerator, lights, internet, and a handful of outlets for 12–24 hours, while a central air conditioner or an electric range can drain the same pack in 2–4 hours, which is why load selection matters more than raw capacity. Cells fade with cycling, and warranties say so plainly: 10 years with roughly 70% of original capacity guaranteed at the end.

These are quiet machines, and quiet machines get ignored until an outage exposes them. Each quarter, clear the vents and the two feet of air space around the cabinet, check the app for cell balance faults and pending firmware, and confirm the reserve setting still fits the season; the battery backup checklist lays out the sequence. Twice a year, flip the main off and run a real 15 minute outage test. Plan on 10–15 years, and once capacity fades, weigh a module swap against a full replacement.