How many watts does a chest freezer use? Three ENERGY STAR sizes, and what they mean in an outage

A chest freezer is the cheapest appliance in the house to keep running through an outage and the one most people forget until the garage smells. Its average draw is tiny, its start-up draw is not, and the two together decide what battery it needs. From the ENERGY STAR listings, a mid-size chest freezer averages 25 to 40 W; the compressor that produces that average starts with a spike its maker does not print. The sizing, with a runtime table and ranked units, lives on the refrigerator page, because a chest freezer wants the same class of inverter.

Three sizes, from the ENERGY STAR dataset

Model (ENERGY STAR listing)	Volume	Annual use	Average draw	Per day
GE FCM11PH	10.6 cu ft	218 kWh	25 W	about 600 Wh
GE FCM16DL	15.7 cu ft	277 kWh	32 W	about 760 Wh
GE FCM22DL	21.7 cu ft	346 kWh	40 W	about 950 Wh

Source: the ENERGY STAR certified residential freezers dataset, read September 11, 2026. Annual kilowatt-hours divided by 8,760 hours gives the average watts, compressor cycling included; the refrigerator wattage guide explains the method and why it beats the nameplate. A chest freezer averages about half of what a same-size refrigerator does, because it is opened less, holds a lower temperature with better insulation, and does not lose its cold air when the lid lifts.

The number the label does not print

The compressor is a capacitor-start motor. When it starts, it draws several times its running current for a fraction of a second, and freezer makers do not publish that locked-rotor figure on the EnergyGuide or the product page. A battery with plenty of watt-hours and a 300 W inverter will hold the freezer’s average draw for days and never start its compressor once. This site’s margin rule, explained in running versus surge watts, is an inverter with at least 1,800 W continuous and 3,000 W surge for any compressor whose start figure is unpublished, and it is why the units on the refrigerator page are the ones to buy for a freezer too.

From watts to a battery

At 25 W average, a day is about 600 Wh at the outlet, about 700 Wh of usable battery once the inverter’s roughly 15% loss is included; the usable capacity guide has that arithmetic. A 1 kWh unit is about 34 hours, a 2 kWh unit about 70. The larger freezers scale with the table. Added to a refrigerator on the same unit, a chest freezer is a modest extra: the sizing calculator carries the 10.6 cu ft figure and adds it in one tick.

The clock that matters more than the battery

USDA guidance is that a full freezer keeps food safe for about 48 hours with the door closed and a half-full one for about 24. A chest freezer is the best case of that rule: cold air stays in when the lid opens, and a full chest of frozen food is its own thermal mass. In a short outage, the honest advice is to leave the lid shut and do nothing. In a long one, a battery that runs the compressor a few hours a day, or a UPS-mode unit ahead of it as the pass-through guide describes, keeps the 48 hours from ever starting. A thermometer inside decides which outage you are in.

Filling the gaps

A freezer that is half empty holds cold for half as long and runs its compressor more. Filling the empty space with jugs of water, frozen ahead of the season, adds thermal mass for the outage and cuts the average draw the rest of the year. It is the one improvement to a freezer’s runtime that costs nothing.