How many days off-grid in your campervan?

Off-grid runtime is not a property of the battery: it is a daily balance between what your panels produce, what the alternator recovers while driving, and what you use. The same van lasts a week in July in Arizona and two days in January in Minnesota, with no change of hardware.

This simulator uses solar irradiation from NASA POWER (satellite/reanalysis climatology) for 18 representative US locations, month by month. The fridge, by far the biggest consumer, is computed by our model calibrated on consumption figures published by Dometic, Vitrifrigo and Isotherm. The result comes as three weather scenarios, never as a single number: between a grey day and a bright one, the same panel varies by a factor of four.