Backup power, in order
Buy it in the order you will need it.
Most people shopping for backup power buy the biggest battery they can afford and still cannot find a flashlight when the lights go out. This site walks five stages, cheapest and most useful first, and each one says what it covers, what it does not, and what to leave in the cart for now. Two things are worth knowing before you read any further: there are no solar panels in this catalog, and there are no fuel-burning generators either. Every unit here called a generator is a lithium battery, and the listings themselves state that the solar panel is optional and sold separately.
The sequence
Five stages, cheapest first. Stop wherever the remaining problems stop mattering to you. Most households should stop before the last one, and the site will say so.
- 00
Before You Buy Anything
This stage costs nothing and closes out more outages than any purchase on this site.
Hours added
None
This stage buys nothing at all.
- 01
Light and a Dead Battery
Two events account for most of what actually goes wrong in an ordinary year: the house goes dark, and the car does not start.
12hoursHours of usable light across an evening and a night. This is the one figure on the site that does not come from the battery formula, because a flashlight is not a power station: it is a planning figure for a household light run on a low setting, and your light's actual runtime is in its manual.
- 02
Phones and the Router
This is where stored energy first earns its place.
9.1hoursHours of a router and a phone on charge from a 288 Wh power station, computed from the same device figures the tables use. Adding a laptop to that load cuts it to under a third. An estimate, not a guarantee.
- 03
The Fridge Through the Night
This is the stage people think they are buying at when they walk into the category, and it is the first one where the specification that matters is not capacity.
17hoursHours of refrigeration from a 1024 Wh unit, with the 35 percent compressor duty share applied and the door kept shut. Computed from the refrigerator device page, so the two cannot disagree. An estimate, not a guarantee.
- 04
Multi-Day and Recharging
Everything before this stage assumes the power comes back.
16hoursHours of a router, phone charging, and a few LED lamps from the largest unit in this catalog. Notice it is not a day, and that is the argument of this whole stage: past one charge the constraint stops being capacity and becomes refilling. An estimate, not a guarantee.
Tool
How long will it actually run?
Pick a capacity and pick the loads. The formula and the derate are printed beside the answer, along with everything the estimate leaves out.
Rated capacity of the battery
What is running
There is no medical or life-sustaining equipment in this list, and there never will be. Powering that equipment is planned with the equipment supplier and with your electric utility, not estimated on a web page.
Sump Pump is also absent from this list. This site publishes no hour figure for that load at all, because the duty share the formula needs is not knowable in the conditions where the load matters, and a figure that cannot stand on its own page should not be quietly added into a total here.
How they run
Estimated runtime
Estimated from 1,024 Wh rated capacity carrying 3 loads drawing 57 W in total. This is an estimate, not a guarantee.
The formula on screen
hours = (rated Wh x 0.85) / (sum of average watts)
- Inverter and usable-capacity derate
- 0.85
- Usable watt-hours after derate
- 870 Wh
- Combined average draw
- 57 W
What this estimate does not account for
- Startup surge. A motor pulls several times its running current for a fraction of a second, and an inverter either supplies that or faults.
- Temperature. A pack in a cold garage gives back less than the same pack indoors.
- Battery age. Cells lose capacity with cycles, and a pack several years old is not the pack on the label.
- The efficiency of your specific model. One derate is applied to every unit here; real inverters differ.
- The real cycling of a refrigerator or freezer, which depends on the room, the contents, and how often the door opens.
- Your actual appliance. The wattages here are ranges; the nameplate on your own device is the figure that applies.
Every figure this tool produces is an estimate, not a guarantee. It does not promise that any unit will run any appliance for any length of time.
What things actually draw
Household loads with the draw this site uses, whether the load has a starting surge, and an estimate of the hours a 1024 Wh unit carries it. Estimates, not guarantees.
| Device | Running draw | Duty share | Average draw used | Surge | Hours from 1024 Wh |
|---|---|---|---|---|---|
| LED Lighting | 30 W | Continuous | 30 W | No | 29 h |
| Phone Charging | 12 W | Continuous | 12 W | No | 73 h |
| Router and Modem | 15 W | Continuous | 15 W | No | 58 h |
| Laptop | 45 W | Continuous | 45 W | No | 19 h |
| Refrigerator | 150 W | 35% | 52.5 W | Yes | 17 h |
| Chest Freezer | 100 W | 30% | 30 W | Yes | 29 h |
| Box Fan | 60 W | Continuous | 60 W | Yes | 15 h |
| Microwave | 1200 W | Continuous | 1200 W | No | 0.7 h |
| Space Heater | 1500 W | Continuous | 1500 W | No | 0.6 h |
The duty share column is what makes the arithmetic checkable. A compressor is not running for the whole hour, so the hours divide the average draw rather than the running draw: average draw is running draw multiplied by the duty share, and hours are (1024 x 0.85) divided by that average. Loads marked Continuous draw their running figure the whole time they are switched on, so the two columns are the same.
One load is missing from this table on purpose. This site publishes no hour figure for Sump Pump, because the duty share the formula would need is not knowable in the conditions where the load matters. A number that swings by a factor of ten on an assumption you cannot check is not an estimate, so there is a page explaining that instead of a figure.
Before anything else
Two things on this page come before any product, because getting them wrong is how people die rather than how they end up with the wrong purchase.
Nothing here ever connects to house wiring
- Do not plug a power station, an inverter, or a generator into a wall outlet in your home. There is no correct way to do it and no cord that makes it safe.
- Feeding a portable source backward into house wiring sends power onto a utility line that crews outside believe is dead, and it bypasses every overcurrent protection in the house.
- The legitimate way to put house circuits on backup is a transfer switch installed by a licensed electrician, with a permit and an inspection behind it. This site does not cover that work.
This catalog has no fuel generators, and here is the one thing worth saying about them
- Every unit sold here is a lithium battery. There is not one fuel-burning generator in this catalog and there is no plan to add any.
- If you own one anyway: it runs outdoors only, well away from windows, doors, and vents. Never in a home, garage, basement, shed, porch, or carport, and an open door does not change that.
- Carbon monoxide from an engine has no color and no smell, and it can reach a lethal concentration in minutes in an enclosed space.
Gear
Five categories, 40 products, each category named by the one job it does. Products live on these pages and appear inside a stage only where that stage genuinely needs hardware.
Portable Power Stations
Core job: storing watt-hours and giving them back as household AC
Open this categoryJump Starters
Core job: getting one engine started without a second car
Open this categoryFlashlights
Core job: seeing, in the first ten seconds and the tenth hour
Open this categoryBattery Chargers & Maintainers
Core job: keeping a battery from dying while it sits
Open this categorySurge Protectors & Power Strips
Core job: one outlet becoming several, safely
Open this category
How this site is written
- Nothing here has been tested by us. Every product specification is what the listing states, and where a listing states nothing, the page says so rather than filling the gap with a plausible number.
- Every runtime figure is an estimate produced by one printed formula, not a guarantee. Nothing on this site promises that a unit will run an appliance for a stated time.
- Medical and life-sustaining equipment does not appear anywhere on this site, in any list or any calculation. That planning belongs with the equipment supplier and with your electric utility.
- Nothing here connects to house wiring. Powering house circuits from a portable source is a licensed electrician’s job with a transfer switch, and it is outside what this site covers.
- There are no prices and no ratings on this site. Prices move and ratings are not ours to report.
- Product links earn BackupWattCache a commission. That does not change the order of the stages or which category a stage points at.