About

About RVPowerCalc

RVPowerCalc publishes calculators and buying guidance for RV electrical systems: house batteries, solar, inverters, converters, DC-DC charging, shore power, wiring and fusing. There are 16 calculators, 262 worked sizing pages and 102 verified components in the catalog.

Where the figures come from

Conductor resistance comes from NEC Chapter 9 Table 8. Ampacity comes from NEC Table 310.16 and from ABYC E-11, and pages say which table they used because the two differ substantially. Overcurrent sizing follows NEC 210.20(A). Shore power ratings come from the NEMA device configurations. Component specifications come from manufacturer listings.

Planning figures that no standards body publishes, such as the 50 percent lead-acid depth of discharge guideline or a solar derate factor, are labeled as conventions everywhere they appear. Mixing the two is how bad electrical advice spreads, so we keep them visibly apart.

What we do not do

We do not test products in person, and we never write as though we have. Recommendations are compiled from published specifications, owner manuals and the consensus of verified owner reviews. Where no genuine product exists for a category, we say so and link a scoped search rather than inventing a pick.

We also do not guess. Where a calculation falls outside the published tables, the calculator returns no answer and explains why, instead of extrapolating past the end of a table.

How the recommendations are chosen

Every component in the catalog was pulled from the Amazon Product API and then checked by reading the returned title against what the page claims. That step matters more in this category than most: a search for a deep cycle house battery returns cranking batteries rated in CCA, a search for LiFePO4 returns lead-acid AGM, and a search for an inverter charger returns plain inverters. Those were all rejected rather than published.

Contact

Questions, corrections and partnership enquiries go to the contact page. Corrections are genuinely welcome: if a figure here disagrees with a published standard, we want to know.