RV and campervan power architecture: 12V fridge loads, charging while driving, solar input, footprint, and LiFePO4 selection

Begin a specification by making a load spreadsheet. Record continuous and peak watts, duty cycle, and runtime expectations. Typical mobile loads include 12V compressor fridges, ventilation, lighting, a CPAP machine, and camera charging gear.

12V fridge loads: measure or obtain the fridge’s nameplate and cycle duty from the manufacturer. Many compressors draw higher current on start-up; list both continuous and peak currents for inverter and DC-DC design.

CPAP machines: CPAPs are critical loads. For procurement, confirm the model’s DC input requirements and typical consumption. Questions to answer: how to power a CPAP while camping, and how many watt hours does a CPAP need overnight for the intended model. Different CPAPs vary widely—specify exact model numbers when requesting samples and documentation.

Charging while driving commonly uses the vehicle alternator via a DC-DC charger. Specify alternator capacity, accessory loads, and target charge rate (amps). For safety and compliance, ensure the DC-DC charger matches battery chemistry (LiFePO4) and charging profile.

When requesting factory samples, require DC-DC charger test logs and a description of BMS behavior under engine-start transients. For fleet installations, document installation preparation items such as cable routing, fuse placement, and thermal considerations.

Solar sizing ties directly to fridge duty cycle and CPAP runtime. Use seasonal solar insolation for the deployment region (US/EU) and derate panels for shading and temperature. For system-level design, specify maximum solar input voltage and MPPT limits so the supplier can match the portable power station or LiFePO4 battery system.

Factory testing should include MPPT behavior, input transient handling, and recovery after shading or partial disconnects. Request test reports showing charge acceptance versus irradiance for the full system.

Footprint affects where the battery and portable power station are installed. Provide internal cabinet dimensions and preferred mounting orientation. For LiFePO4 packs, thermal management and ventilation spacing are critical—request thermal test data from the factory.

For larger builds, include model-specific documentation checks: enclosure IP rating, vibration testing, and transport packaging. These details should be part of product samples and pre-shipment inspection for fleet orders.

LiFePO4 is a preferred chemistry for RV and campervan systems because of cycle life and safety. When specifying a LiFePO4 solution, verify chemistry details, BMS behavior, cell balancing approach, and end-of-discharge limits. Do not accept assumptions—request the exact certificates and test reports for the model you will purchase.

For compliance across the United States and EU, buyers must confirm transport documents, UN38.3 test evidence for shipping lithium batteries, and any required CE/UKCA declarations for accessory electronics. Factory testing and sample approval must include runtime verification under realistic loads and temperature ranges.

CPAP users need reliable power. For procurement, ask: does the unit require AC or DC? If the CPAP accepts DC, a CPAP portable power station with DC output can be more efficient than inverting from a battery. Always calculate how many watt hours does a CPAP need overnight for the specific model and include a margin of 30–50% for user comfort and warm-up (humidifiers).

For photographers, list use cases: running LED lighting, charging camera batteries, tethered laptop use, and fast camera battery chargers. A portable power station for photography should document DC and AC outputs, simultaneous output limits, and recommended battery charging profiles for camera lithium packs. Ask factories for runtime tests with representative camera charging loads.