What Size Battery Do I Need for a 12V Fridge?
SUNCOAST BATTERIES & SOLAR
Plan in watt-hours before choosing amp-hours.
Start with the decision that matters
Measure daily use
Use measured Wh per day or relevant manufacturer consumption data. Ambient temperature, thermostat setting, ventilation and opening the lid can change consumption.
Allow usable energy
Compare the required energy with manufacturer-permitted usable energy, not just nominal capacity. Include system losses and a reserve.
Three checks before you order
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Add the daily loads
List fridge energy and all other loads, including lighting and standby consumption. Keep watts (power) separate from watt-hours (energy).
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Choose the time away
Multiply daily energy by days without dependable recharging. Do not count on full solar output every day or a short drive replacing all energy used.
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Check the battery and charger
Verify usable-energy limits, current capability, mounting and charging compatibility. Send the fridge model, trip pattern and charger details for a quote.
Explore the range
Check the current product details and send us your application before choosing a model.
Questions before you buy
Worked example: two days without recharge
Illustration only: assume 300 Wh/day for a fridge and 60 Wh/day for other loads, measured at the appliances. Two days need 720 Wh. At an assumed 90% delivery efficiency, the battery must supply 800 Wh. Adding a 20% reserve gives a 960 Wh usable-energy target. These are planning assumptions, not measured performance or a runtime guarantee. Select nominal capacity only after checking the exact batteryβs permitted usable energy.
Can I divide by 12 to get the battery size?
Dividing Wh by nominal volts gives an approximate Ah equivalent, not the required label capacity. Usable-energy limits and losses still need allowance.
Can I use my starter battery?
Do not plan camping loads around an unverified starting reserve. Discuss a suitable auxiliary arrangement and the vehicle requirements.
Manufacturer references
Technical background; use the instructions for your exact equipment.
References open in a new tab.
Ready to narrow down your options?
Send the details above and your suburb for a clear quote. Product availability, delivery and any fitting need confirmation for your application.
Friendly help, flexible payment options and no pressure. Ask us for an obligation-free quote and letβs get your battery sorted. Afterpay and card payment on delivery available. Ask about options when booking. Afterpay eligibility and terms apply.