The duration a mini fridge will run on a deep-cycle battery depends on several factors, including the battery's capacity, the fridge's power consumption, and the efficiency of the battery and inverter system. Here's a general approach to calculating the estimated runtime:
Battery Capacity: Determine the capacity of the deep-cycle battery in ampere-hours (Ah). This information is typically available on the battery's label or specifications.
Fridge Power Consumption: Find out the power consumption of the mini fridge in watts. This information can usually be found on the fridge's label or in the user manual.
Inverter Efficiency: If you're using an inverter to convert the battery's DC power to AC power for the fridge, consider the inverter's efficiency. Inverters are not 100% efficient, so a portion of the energy will be lost as heat during the conversion process.
Once you have these values, you can calculate the estimated runtime using the following formula:
Estimated Runtime (in hours) = (Battery Capacity in Ah * Battery Voltage) / (Fridge Power Consumption in Watts * Inverter Efficiency)
For example, let's say you have a deep-cycle battery with a capacity of 100 Ah, a mini fridge that consumes 60 watts, and an inverter with an efficiency of 90%. The battery voltage is typically 12V for deep-cycle batteries.
Estimated Runtime = (100 Ah * 12V) / (60W * 0.9) ≈ 22 hours
Keep in mind that this is an estimated runtime, and real-world conditions may affect the actual performance. Factors such as the ambient temperature, battery age, and other devices connected to the battery will also influence the runtime. It's always a good idea to have some extra capacity in the battery and to monitor the battery's charge level regularly to avoid deep discharges, which can harm the battery's health.