Mac's Batteries & Solar — Eugene, OR
Mac's Batteries & Solar
12V July 2026

RV Whole-Coach 3000W Build

RV — Whole-Coach Power

A 12V RV build sized to run the entire coach — a 3000W Renogy inverter, a 900Ah LiFePO4 bank across three 300Ah batteries, a 100A charging system, dual AC transfer boxes, distribution bars, and heavy Temco cable throughout.

RV under-seat battery compartment with lithium batteries, inverter, DC-DC charger, and AC transfer boxes wired together

Components in This Build

  • Renogy 3000W pure sine wave inverter (12V)
  • 3x 300Ah LiFePO4 batteries (900Ah bank)
  • 100A charging system
  • 2x AC transfer boxes (shore / generator / inverter switching)
  • Distribution bars
  • Fuse
  • High-gauge Temco welding cable wiring

This system was built to power an entire RV coach, not just a handful of circuits. A 3000W Renogy inverter and a 900Ah 12V LiFePO4 bank (three 300Ah batteries) give enough capacity and surge headroom to run AC appliances alongside everything else in the coach.

A 100A charging system keeps the bank topped off, and two AC transfer boxes let the RV automatically or manually switch its AC power source between incoming shore power, a generator, or the inverter itself — so the coach stays powered no matter which source is available.

Distribution bars cleanly split power to the coach’s circuits, a fuse protects the main run, and everything is wired with high-gauge Temco welding cable sized for the full 3000W load.

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