How many amp hours is a 1,000 Wh power station?
Power basics Updated 2026-08-16
Watt-hours measure energy and amp-hours measure electric charge — two different physical quantities — and the formula that connects them needs a number almost no listing prints: the battery pack’s own voltage. Divide watt-hours by that voltage and the result is amp-hours; assume the wrong voltage and the answer is wrong by exactly the ratio the two voltages differ by.
A generic Wh-to-Ah calculator assumes a 12 V lead-acid battery. Divide a real 1,024 Wh EcoFlow Delta 3 Plus by that assumption and it reports 85.3 Ah. Divide by the pack’s own 51.2 V instead — printed on the same spec sheet — and the true figure is 20.0 Ah, a 4.27× gap a 12 V assumption cannot see.
Two quantities, one missing number
The relationship is simple: multiply a battery’s voltage by the charge it delivers and the product is the energy stored — volts × amp-hours = watt-hours. Every lead-acid starting battery on the market is built to the same 12 V standard, which is why a car or marine amp-hour rating converts to watt-hours without asking. A power station’s lithium pack is not built to any single standard voltage: manufacturers wire cells in series to whatever pack voltage suits their own inverter design, and among the station records this library holds a figure for, that number spans 12.8 V to 51.2 V — a fourfold range.
Seven records, a fourfold spread, one formula
Nominal pack voltage — and the amp-hours it implies
The voltage in each row is the manufacturer’s own published figure, with its tier and date attached; the division beside it is this site’s own, never theirs. Six of the seven spec sheets also state the amp-hour number directly, in the same sentence as the voltage — our division agrees with every one of them to a tenth of an amp-hour.
Nameplate 288 Wh ÷ this voltage = 22.5 Ah.
See the record →Nameplate 1,920 Wh ÷ this voltage = 100.0 Ah.
See the record →Nameplate 286 Wh ÷ this voltage = 12.8 Ah.
See the record →Nameplate 1,070 Wh ÷ this voltage = 30.4 Ah.
See the record →Nameplate 1,264.6 Wh ÷ this voltage = 30.4 Ah.
See the record →Nameplate 1,024 Wh ÷ this voltage = 20.0 Ah.
See the record →Nameplate 4,096 Wh ÷ this voltage = 80.0 Ah.
See the record →Official specverified 2026-08-01Seven US station records with a published pack voltage
One CPAP, two very different amp-hour numbers
The gap is not academic once you put a real load through it. A CPAP machine running its humidifier draws the same watt-hours in a night whichever station it is plugged into — the amp-hour figure that energy represents does not.
The same night on two different stations
ResMed’s own measured table for this configuration gives the nightly energy; the two rows beneath it are this site’s own division of that one figure by two different stations’ pack voltages.
ResMed's 22 W for this device with the humidifier on, times the 8 h night its own battery guide sizes against — not a figure the maker states as a single number.
See the load record →this site's own arithmetic: the 176 Wh nightly figure above ÷ this station's 12.8 V pack voltage
See the pairing →this site's own arithmetic: the same 176 Wh nightly figure ÷ this station's 51.2 V pack voltage
See the pairing →Derived by WattPairverified 2026-08-01CPAP machine (humidifier on) × two station pack voltages
None of this changes what a verdict on this site is computed from. Every runtime and every compatibility check on this site divides usable watt-hours — never amp-hours — and a pack voltage never enters that division; the runtime calculator asks for a load in watts and a station’s watt-hour capacity, nothing else. Amp-hours are worth converting to when you are sizing against a car or marine battery you already own in amp-hours. For sizing a power station against a load, watt-hours was always the right number.