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How to size a battery for a 12V fridge

August 28, 2026

Last updated August 28, 2026. Not a lab test. Hours are arithmetic: published Wh ÷ cited watts. Compressors cycle.

A 12V compressor fridge is a load. Size the battery from two published numbers: the fridge’s watts, and the battery’s watt-hours.

Hours ≈ battery Wh ÷ cited watts.

That divide is a 100% duty-cycle ceiling, not a camp test. Compressors cycle, so real hours are shorter. Run the fridge on a power station’s AC outlet and inverter loss shortens them again. DC 12 V skips the inverter.

Three current catalog units below. Watts, Ah/h, and Wh are the makers’ printed figures. ECO watts, fridge Wh, and duty cycle are marked unknown where the spec table does not print them.

Index

ICECO 21QT GO20 Dual Zone

ICECO’s US page names it a 21 QT GO20 Dual Zone 12V portable freezer. The official GO20 blog lists 20 L. Interior as a single zone: 13.8 × 9.5 × 9.3 in.

In Max mode ICECO says consumption is around 45 W. The Canada GO20 page says the same as “fully operating for Fast cooling is 45 W.” ECO watts are not published. Fridge Wh is not published. The US page mentions a PB250 battery and does not print a Wh next to it. There is no ICECO Wh ÷ W line.

ICECO official store

Dometic CFX3 35 (SKU 9600024617)

Dometic’s US page lists a powered 12 volt cooler, 36 L. Input: DC 12/24 V, AC 120 V. Rated input power (AC): 50 W. Rated input current (AC): 0.78 A at 120 V. Rated input current (DC): 7.5 A. Do not treat 7.5 A as average draw.

Energy consumption at 12 V DC, Ambient @ 90 °F, Internal @ 39 °F: 0.98 Ah/h.

Arithmetic (not a test): 0.98 Ah/h × 12 V = 11.76 Wh per hour under that stated condition. That converts Dometic’s Ah/h row. It is not a field test. The cooler has no published energy store, so there is no matching fridge Wh and no battery-hours line for the box alone.

Dometic official store

BougeRV CRD2 V2.0 61QT

BougeRV’s product page lists 61 Qt = 58 L, rated power input 60 W, DC 12/24 V and AC 100–240 V. Optional detachable battery: 240 Wh.

Arithmetic (not a test): 240 Wh ÷ 60 W = 4.0 hours of continuous 60 W draw. That is a 100% duty-cycle ceiling from cited numbers. Duty cycle is not published.

BougeRV official store

BougeRV CRD2 V2.0 61QT on Amazon

Use the same divide on a power station

Take the station’s published watt-hours and divide by the fridge number you actually have. The 240 Wh kit is the only matching battery Wh on these three pages. 240 ÷ 60 = 4.0 hours at rated input — same ceiling as above, not a test. Dometic’s 11.76 Wh per hour is a consumption rate under a stated condition, not a pack size. ICECO has no official matching Wh, so do not invent an ICECO runtime.

Confirm DC versus AC on the station you own. See the guides hub and portable power stations.

Cited numbers

ProductCapacityCited watts or Ah/hArithmetic hoursSource
ICECO 21QT GO20 Dual Zone21 QT / 20 LMax ~45 W (ECO unknown)No matching WhICECO
Dometic CFX3 3536 L0.98 Ah/h @ 90 °F / 39 °F, 12 V DC; AC rated 50 W11.76 Wh/h (Ah/h × 12 V); no matching fridge WhDometic
BougeRV CRD2 V2.0 61QT61 Qt / 58 L60 W rated; optional 240 Wh battery4.0 h at 60 W continuousBougeRV

Sources

Re-fetched 28 August 2026. Cited numbers match the 24 August research file. No substitutions.

  1. https://icecofreezer.com/products/21qt-go20-dual-zone-fridge-white
  2. https://icecofreezer.com/en-ca/products/iceco-go20-flexible-dual-zone-12v-car-fridge (45 W Max)
  3. https://icecofreezer.com/blogs/iceco-fridge-guidance/go20-small-but-mighty-refrigerator (20 L)
  4. https://www.dometic.com/en-us/product/dometic-cfx3-35-9600024617
  5. https://www.bougerv.com/products/12v-compressor-fridge-freezer
  6. https://www.amazon.com/BougeRV-Portable-Refrigerator-Compressor-Overlanding/dp/B0GHMBX3P1 (ASIN B0GHMBX3P1 confirm only)
How do you estimate 12V fridge runtime from a power station?

Hours ≈ battery watt-hours ÷ the fridge’s cited watts. That is division, not a field test. Compressors cycle, so real hours are shorter than a 100% duty-cycle ceiling.