Wh to Ah: you need the voltage
Watt-hours convert to amp-hours only once you know the voltage. A table for common capacities at 12, 24 and 48 V.
There is no single answer here, because the result depends on the system voltage. Divide watt-hours by volts and you get amp-hours. A 512 Wh station is 42.7 Ah at 12 V but only 21.3 Ah at 24 V — same energy, different charge.
Manufacturers quote watt-hours precisely because they are unambiguous. Amp-hours mean nothing without a voltage, and the internal voltage of a power station is rarely a round 12 V; more often it lands somewhere in the teens or higher, depending on how the cells are arranged.
If you are converting in order to compare a station against a battery, compare watt-hours with watt-hours. Moving to amp-hours earns its keep later, when you size cables or a fuse, because that is where current decides.
Common station capacities
| Energy | At 12 V | At 24 V | At 48 V |
|---|---|---|---|
| 299 Wh | 24.9 Ah | 12.5 Ah | 6.2 Ah |
| 504 Wh | 42 Ah | 21 Ah | 10.5 Ah |
| 512 Wh | 42.7 Ah | 21.3 Ah | 10.7 Ah |
| 1024 Wh | 85.3 Ah | 42.7 Ah | 21.3 Ah |
| 2048 Wh | 170.7 Ah | 85.3 Ah | 42.7 Ah |
Usable capacity is not the rated figure
The number on the case usually describes the rated energy of the cells. What you get is less: the converter loses somewhere over ten percent, and the maker holds back a margin at the bottom of the range so the battery lasts. On lithium stations, count on roughly 85 percent of what the label says.