A typical 12V compressor fridge running on a 100Ah LiFePO4 battery can usually last 20–50 hours. The exact runtime depends on several factors: the fridge’s average power consumption (typically 35–55W), ambient temperature (hotter conditions increase power draw), temperature settings (fridge mode uses less energy, freezer mode can double consumption), and how often the door is opened (frequent opening makes the compressor run more).
In cooler weather with fridge mode and minimal door openings, runtime can reach 40–50 hours, while in hot conditions or freezer mode, it may drop to around 20 hours. Overall, a 100Ah battery typically supports 1–2+ days of reliable operation for most 12V compressor fridges.