Device runtime library

What each appliance needs to run

Pick an appliance to see its sourced average draw, startup surge, a four-step runtime ladder, and the stations that pass the same sizing math.

Runtime answers

How to read these pages

Two numbers decide the answer

Continuous watts decide whether a station can carry the appliance at all; watt-hours decide how long. A big battery behind a small inverter fails the first test, and a large inverter on a small battery passes it for twenty minutes. Every page shows both.

Surge is the hidden failure

Anything with a compressor or motor — a fridge, a well pump, an air conditioner — pulls a multiple of its running draw for a fraction of a second at start. Where a device’s surge has not been published, the check reads unverified rather than pass, because a guess here is the difference between a plan that works and an appliance that never starts.

Duty cycle, not clock hours

A refrigerator plugged in for 24 hours does not draw power for 24 hours. Each page states the assumed hours of actual operation and computes energy from that, so the runtime ladder reflects how the appliance behaves rather than how long it sits connected.

The projections are nominal

Runtime at 300, 500, 1,000, and 2,000 Wh is computed from usable capacity after depth-of-discharge and inverter losses. Cold weather, an aging pack, and a heavier-than-typical unit all shorten it, which is why the pages recommend margin rather than an exact fit.

Running several of these at once? Size the whole situation instead.

How to use the appliance library

These pages answer one question at a time: this appliance, this class of battery, how many hours. That is narrower than the question most people arrive with, and narrow is usually the right place to begin — a plan you cannot check one line at a time is a plan you cannot debug when it disappoints you.

Begin with what you are least willing to lose

The instinct is to look up the biggest load first, and it is the wrong end of the problem. The appliance that decides a purchase is the one whose failure you would not accept — a CPAP, a refrigerated medicine, the freezer holding a month of food. Settle that page first, then spend whatever headroom is left on comfort. It is a much shorter route to a decision than totalling everything up and negotiating downward.

Nameplate order and daily-cost order barely resemble each other

Sorting appliances by the number printed on them produces a list almost unrelated to sorting them by what they cost you in a day. Things that draw enormously for a few minutes turn out to be affordable; things that draw modestly and never switch off turn out not to be. This library rewards browsing rather than searching for exactly that reason — the appliance you were worried about is often cheap, and the one you never thought about is often the reason a plan runs short.

Why some of these pages are not in search results

Every appliance here renders a complete sourced answer, but only pages carrying hand-written, appliance-specific analysis are put forward for indexing. If a page could have been produced by swapping a name and three numbers into a template, it stays out of the index while remaining fully linked and fully usable. That standard was adopted deliberately, and it is why this index is longer than the set of pages a search engine will show you.

What to do with the number once you have it

A runtime figure is a planning input, not a verdict, and the honest move is to round it down. Then decide whether the gap you are left with closes better by buying more battery or by making a smaller assumption — an hour less of use, a lower setting, one load moved onto a different fuel. On most of these pages the second option is cheaper than the first by an order of magnitude, and nothing in a specification sheet will ever suggest it to you.

Only topics with a complete sourced device record are published. Refrigerator and CPAP retain their existing canonical guide and calculator owners.