Will RV fridge run off battery while driving?
Yes, most RV refrigerators can run off the battery while driving if properly configured. Modern RV fridges often support dual power sources—12V DC battery power during transit and 120V AC or propane when parked. The vehicle’s alternator typically charges the battery while driving, sustaining fridge operation. However, battery capacity and fridge energy efficiency determine runtime. For example, a 12V compressor fridge drawing 5A can operate ~20 hours on a 100Ah lithium battery. Pro Tip: Use lithium batteries (LiFePO4) for faster alternator charging and deeper discharge cycles compared to lead-acid.
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How does an RV fridge stay powered during transit?
RV fridges switch to 12V DC battery power when unplugged from shore power. While driving, the alternator charges the battery, creating a closed loop. High-efficiency compressor fridges (e.g., Dometic CFX3) consume 40-60Wh/hour, while absorption models use 100-150Wh. Always verify your fridge’s voltage compatibility—older units may require propane.
What battery type is optimal for RV fridge support?
Lithium iron phosphate (LiFePO4) batteries outperform lead-acid with 80-100% usable capacity vs. 50%. A 200Ah LiFePO4 battery can power a 5A fridge for ~40 hours. They also charge 3x faster from alternators (accepting up to 100A vs. 30A for AGM). Weight savings (50% lighter) further benefit fuel efficiency.
| Battery Type | Usable Capacity | Alternator Charge Rate |
|---|---|---|
| LiFePO4 | 80-100% | Up to 100A |
| AGM | 50% | Max 30A |
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FAQs
Not recommended—standard fridges need 120V AC inverters, doubling energy loss. Use 12V DC compressor models instead for 30% higher efficiency.
How to prevent battery drain while driving?
Install a DC-DC charger to optimize alternator output. Basic setups risk undercharging—LiFePO4 needs 14.4V absorption, which most alternators don’t sustain without voltage boosters.