Where I live, the power goes out maybe twice a year (typically for between half an hour and maybe five or six hours, depending on the fault). Where my mother li

Where I live, the power goes out maybe twice a year (typically for between half an hour and maybe five or six hours, depending on the fault). Where my mother lives, in the country, it could go out for two days when it goes. Luckily its not that often, but when it does, there's never an advance warning. If your life depends on continuous power, planning for an occasional no-warning outage seems like the prudent thing to do.