Glossary

A unit of energy: one watt drawn for one hour. It is the honest way to state how much a power station holds, because it already accounts for voltage. Divide a capacity in watt-hours by a load in watts and you get hours, which is why every estimate on this site starts here.

A unit of charge, not energy. An amp-hour becomes watt-hours only once multiplied by the voltage the rating was taken at, and listings often use the raw cell voltage rather than the voltage the device delivers. Two products with the same milliamp-hour figure can hold different amounts of energy.

The wattage an inverter will supply indefinitely. This is the figure that decides what you can run for an evening, and it is the only one worth comparing between units. Where a listing states no continuous figure, this site records it as not stated rather than inferring one.

A higher wattage an inverter will supply for a very short interval before protecting itself, sometimes labeled peak. Motors need it to start. A unit whose continuous rating comfortably exceeds a motor's running wattage can still refuse to start it, because the starting demand exceeds the peak.

The circuit that converts stored direct current into the alternating current a household plug expects. It is why the outlets on a power station work and why what comes out is less than what the cells hold. Its rating, not the battery capacity, decides what will run.

An inverter output waveform that closely matches what the utility delivers, as opposed to a modified or stepped approximation. Some electronics and motors run poorly or noisily on the approximation. Where a listing states a waveform, it is worth noting; where it does not, the manual is the place to look.

Lithium iron phosphate, a lithium cell chemistry commonly used in power stations and stated on most of the units in this catalog. Manufacturers generally associate it with a higher rated cycle life than other lithium chemistries. Storage and charging temperature limits still come from your model's manual, not from the chemistry name.

The number of charge and discharge cycles a manufacturer rates a pack for before its capacity falls to a stated fraction of new. It matters most for a unit that sits for years and gets used rarely, since the pack you bought is not the pack you have after several seasons. It is a manufacturer rating, not a guarantee.

How far a pack is run down before recharging, expressed as a share of its rated capacity. Packs are generally not run to absolute zero, which is one reason rated watt-hours are more than delivered watt-hours. This site folds that gap, along with inverter loss, into a single 0.85 derate.

Running a load from a power station while the station itself is charging. Some units support it and some do not, and some support it with restrictions. The manual for your model is the only reliable source on whether yours does.

The share of an hour a load actually draws power. A refrigerator compressor runs until the box is cold, stops, and restarts, so its average draw across an hour is far below its running wattage. Duty cycle makes motor loads cheaper than the label suggests, while surge makes them harder.

Pushing current from a portable source backward into house wiring, which sends power out onto a utility line that crews outside believe is dead. It has killed line workers and it bypasses every overcurrent protection in the house. There is no safe improvised version of it, and this site describes none.

A device installed by a licensed electrician that makes it physically impossible for a house to be connected to the utility and a portable source at the same time. It is the legitimate way to put house circuits on backup power, and it is a permitted, inspected trade job. This site does not cover that work.

An uninterruptible power supply, which sits between the wall and a device and carries the load through the instant utility power drops, fast enough that a computer does not reboot. Most power stations do not do this; you notice the outage and plug things in. Where a unit claims a fast transfer mode, the manual is where to confirm it.

A figure sellers publish for how much surge energy a protector can absorb over its life. On this site those numbers are reported exactly as each listing states them and are not treated as measurements, because the test conditions behind them are not published in any way a buyer can check. A certification mark is the more useful signal.

Plugging one power strip into another, or into an extension cord, or into a wall outlet extender. It defeats the protection circuitry, hides how much load is sitting on one receptacle, and is a recognized fire cause. One strip, straight into the wall, is the whole rule.

A large current figure quoted on jump starter listings, such as 4000A or 8000A. This site reports those numbers as the listings state them and does not compare products by them, because the conditions behind the figure are not standardized across sellers. The stated engine displacement range is the more meaningful number.

A rating describing current a battery can deliver for a short period at a specified temperature, used mainly for vehicle starting batteries. It is defined by a published test standard, which is what distinguishes it from an unqualified peak amp claim. Where a jump starter listing does not name a standard, treat the number as a seller claim.

A charger that supplies a small, steady current. Simple trickle chargers keep pushing after a battery is full, which can damage it over a long connection, while automatic units step down instead. Check whether a unit stops or floats before leaving it connected for a season.

A charger designed to be left connected indefinitely, holding a full battery at full rather than filling an empty one. It is the answer for a vehicle that sits between seasons. A maintainer will recover a flat battery eventually, but slowly enough that it is the wrong tool for the job.

A mode several chargers state, described as an attempt to recover a lead-acid battery that has been left discharged for a long period. Treat it as a stated feature rather than a promised recovery, and read what your manual says the mode actually does before selecting it. It does not apply to lithium packs.

A measure of total light output from a source. It separates a keychain light from a household one but says nothing about how far a beam throws or how evenly it spreads. Indoors, a high lumen figure mostly produces glare, and the low mode is what carries a long evening.

How long something runs before it stops. On this site every runtime figure is an estimate produced by dividing derated watt-hours by a steady wattage, with the formula printed on the page. It is a planning figure and never a guarantee that a particular unit will run a particular appliance for a particular time.

A listing phrase meaning the unit has an input port that will accept a solar panel. It does not mean a panel is included, and the phrase solar generator means the same thing. There are no solar panels in this catalog, no unit here ships with one, and this site does not estimate solar recharge times.