WattPair — a power-station calculator that refuses to print numbers it can't source

Built this over six months of nights and weekends: wattpair.com answers "will this battery power station actually run my fridge / CPAP / air conditioner - and for how long."

The twist: I have no lab, so the engine only uses manufacturer-published numbers, and when a number doesn't exist it says so instead of guessing. 23 of my 29 station entries have no published usable capacity - those pages print no runtime at all, with the reason.

One result that surprised me: none of the 29 units can start a typical RV rooftop air conditioner (1,690 W running, 8,619 W at start-up vs an 8,000 W best-in-library surge ceiling). Every watts-only comparison table says yes.

Calculators are free, no signup, results shareable as URLs: https://wattpair.com/tools/

There's also an open CC-BY dataset of every U-shaped window AC sold in the US (204 models with derived running watts): https://wattpair.com/data/u-shaped-window-ac/

Disclosure: product pages carry affiliate links; verdicts are computed before any retailer is looked up. Happy to answer anything about the honest-data mechanics.