12V fridge power calculator

Estimate a compressor fridge's daily energy use from its running watts and duty cycle, then size a LiFePO4 battery for days without charging.

Fridge compressor running power (W)Estimated compressor duty cycle (%)Days without recharging (days)Other daily loads (Wh/day)

Estimated daily use: 528 Wh

41.3 Ah/day at 12.8 V equivalent.

Battery planning estimate: 120 Ah LiFePO4

Based on 1,056 Wh across 2 days, 80% usable capacity and 90% system efficiency.

Fridge duty cycle varies considerably with ambient temperature, insulation, ventilation, contents and lid openings. Check manufacturer energy-consumption data where available.

Planning estimates only. Real-world consumption varies with temperature, usage, equipment specifications and system losses. Consult a qualified installer for electrical design, wiring and protection.