Generator vs Battery Calculator
Describe the outage you are planning for. We compare a home battery, a standby generator and a portable generator on cost, runtime, fuel, noise and upkeep. Sometimes the generator wins.
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How we keep this comparison fair
SentryVolt does not sell batteries or generators. The verdict above comes from the same scoring used in the Power Plan: each option is judged on whether it can supply your power, whether it lasts as long as you asked, how much manual effort it takes, and what it costs relative to the size of the need. A generator wins this comparison often, particularly for multi-day outages and whole-home loads.
Things a table cannot decide for you
- Your fuel situation. Natural gas service makes a standby generator far more convenient. Without it you are sizing and refilling a propane tank.
- Your neighbors and your HOA. Some communities restrict generator placement or operating hours.
- How outages actually happen where you live. Frequent short flickers reward a battery. Rare multi-day storm outages reward fuel.
- Whether you want solar. A battery stores solar; a generator does not.
For more depth, read Solar Battery vs Generator.
Get a recommendation that also weighs solar, efficiency and your budget.
Build My Power Plan →Common questions
Neither is better in general. Batteries suit short and medium outages, modest loads, and homes where noise, fuel or maintenance are a problem. Generators suit long outages, large loads such as central air, and homes with natural gas service. Many homes are well served by a small battery plus a generator.
For a given amount of backup, a generator usually costs less upfront, and the gap widens as the outage gets longer or the load gets larger. A generator then costs fuel and maintenance every year, while a battery costs almost nothing to run. For short outages with essential loads only, the totals can be close.
On natural gas, as long as gas service continues and the unit is maintained. On propane, until the tank is empty: the calculator estimates how many days a tank lasts at your load. Extended runs still need oil checks and service at the intervals the manufacturer specifies.
Yes for selected circuits, when it is connected through a transfer switch or an inlet with an interlock installed by a licensed electrician. Plugging a generator into a household outlet is dangerous and illegal: it can energize utility lines and injure line workers. Always run a generator outdoors, well away from doors and windows.