Power station terms, in plain words

Terms

Read the first four and you can read any spec sheet: watt-hours say how long, watts say how much at once, surge says whether a motor will start, and chemistry says how many years it lasts.

Wh (watt-hour)

the energy the battery stores. A 1,000 Wh unit can supply 100 W for about 10 hours before losses. This is the capacity figure on every spec sheet and the one the sizing calculator solves for.

kWh (kilowatt-hour)

1,000 Wh. Brands use it for large units; this site converts everything to Wh so rows compare.

W (watt), continuous

the power the inverter can deliver steadily through the AC outlets. Every device you run at once adds up against this number.

Surge W (peak W)

the short burst the inverter can deliver for a fraction of a second to a few seconds, which is what a compressor or a motor draws when it starts. A fridge rated 100 W running can pull 800 to 1,200 W at start-up.

Boost mode (X-Boost, Power Lifting and similar)

a manufacturer mode that runs a resistive load (heater, kettle) above the continuous rating by lowering the voltage. It is not the continuous rating and this site never records it as one.

LiFePO4 (LFP, lithium iron phosphate)

the cell chemistry now used by most current units. Typically rated 3,000 to 4,000 or more cycles, heavier per Wh, and more tolerant of heat than NMC.

NMC (NCM, ternary lithium)

the lighter chemistry used in earlier units and some current light ones. Typically rated 500 to 1,000 cycles.

Cycle life

the number of full charge and discharge cycles after which the battery still holds a stated share of its original capacity, usually 80%. '3,000 cycles to 80%' means after 3,000 full cycles the unit still holds at least 80% of its rated Wh. The share matters as much as the count.

Depth of discharge (DoD)

how much of the battery a cycle uses. Manufacturers' cycle claims assume their own DoD, which is why cycle counts across brands are only roughly comparable.

Inverter efficiency

the share of stored energy that reaches an AC device; the rest is lost as heat in the inverter. Manuals typically state 85% to 90%. The calculator divides by 0.85.

MPPT (maximum power point tracking)

the charge controller that draws the most a solar panel can give at any moment. Every current unit has one; the number that matters is the maximum solar input in W, which caps how fast any panel can recharge the unit.

Solar input (max)

the most solar power the unit will accept, in W. A 400 W panel on a unit with a 200 W input charges at 200 W at best.

AC input (max)

the most the unit draws from a wall outlet while charging, in W. Together with capacity it sets the wall recharge time.

Recharge time

the manufacturer's stated time from empty to full (or to 80%, where that is what they publish) from the wall or from solar at the maximum input under their conditions.

UPS / EPS switchover

when the unit sits between the wall and a device, the time it takes to switch to battery when the wall fails, in milliseconds. Under about 20 ms most computers and CPAP machines do not notice; some brands publish 10 ms, some 20 ms, some 30 ms, and some publish nothing.

Pass-through charging

using the unit's outlets while it is charging from the wall or solar.

Expandable

the unit accepts add-on batteries. The maximum expanded capacity is the total Wh with every supported add-on attached.

USB-C PD (Power Delivery)

the USB-C standard that lets a port supply up to 100 W (PD 3.0) or 140 W and beyond (PD 3.1) to a laptop. The table records the highest single USB-C output.

Solar generator

marketing name for a power station sold in a bundle with one or more solar panels. Nothing is generated; the station stores energy and the panel replaces it. The station's specs are what matter.

Price per Wh

the current official price divided by rated capacity. The neutral way to compare cost across sizes; this site's price-sorted tables use it.