For an typical RV scenario, a 100Ah LiFePO4 battery (nominal 12.8V) will provide 1.28kWh usable energy (with an 80% depth of discharge assumption). When the load in the RV is a 50W onboard refrigerator, a 20W lighting system, a 100W TV, and a 10W router, a combined power draw of 180W, the theoretic cruise duration will be 1280Wh/180W≈7.1 hours. But in real operation, the inverter loss (approximately 85% efficiency) has to be included, and effective power supply time is down to 6 hours. According to a survey conducted by the Touring Car Association of America (RVIA) in 2022, the average user’s daily power consumption is between 2 and 3kWh. This suggests that a single 100Ah battery would satisfy only 40% to 60% of the minimum requirement, and at least a solar panel of 200W and more is required as a topping.
In hot or cold environments, LiFePO4 battery stability is greatly better than the other type. For instance, during the 2023 North American cold wave, the Airstream RV with a 100Ah lithium iron phosphate battery would still maintain 85% capacity output when tested at -15℃, while the AGM battery capacity with the same capacity was already down to 55%. When the RV has an installed air conditioner with peak current 125A, for instance, of 1500W, only the 100Ah battery bank can endure up to 0.8 hours under full loading. But in conjunction with utilizing the smart energy management system, say, such as the Victron MultiPlus, the time the air conditioner works in a switched-mode on and off situation can last for up to 2.5 hours with a retention capacity for other devices by setting aside 40% power.
On cost efficiency, the general market price for a 100Ah lifepo4 is approximately $900. Even though 200% more expensive than lead-acid batteries with the same capacity, its life of 3,000 cycles (DOD 80%) can reduce the cost per cycle to as low as $0.3 /kWh, merely 1/4 that of lead-acid batteries. Borrowing from America’s 200 days of average annual travel time among RV users, lithium iron phosphate batteries will last up to 15 years while lead-acid batteries are replaced every two years. Winnebago unveiled the e-RV concept vehicle in 2021, and it was equipped with twin 100Ah LiFePO4 battery packs. It was also verified that it was capable of sustaining power supply continuously for 72 hours in desert conditions at a temperature of 45℃, and the rate of failure in equipment was reduced by 62% relative to the traditional solution.
The scalability test of the load demonstrates that the 100Ah LiFePO4 battery supports a maximum continuous discharge current of 100A (rate of 1C) and an instantaneous peak of 200A (2C). If a 3000W inverter is utilized to power the induction cooker (1800W), the battery pack can discharge 25% of capacity in 15 minutes and subsequently induce overload protection by the BMS. By comparison, the minimum cost of RV modification plan for Tesla Powerwall 2 (13.5kWh) is as high as $8,000, which is five times higher than the lithium iron phosphate battery plan. According to the 2023 “Consumer Reports,” 78% of RV consumers choose 100-200Ah LiFePO4 batteries as their main source of power. With solar, they can provide 3-5 days off-grid range, more than 120% longer than lead-acid battery systems.
Environmental adaptability statistics show that at tropical temperatures with less than 90% humidity, the capacity attenuation rate of LiFePO4 battery is merely 0.3% per month, while that of ternary lithium battery is 1.2%. Australian RV Association data show that 100Ah lithium iron phosphate battery cars have an average mileage between failures (MTBF) gain to 8,500 kilometers in wet season conditions, 210% greater than the lead-acid battery counterpart. If 1.5kWh of electricity is consumed by the user each day (including the pump for water, ventilation system, etc.), the 100Ah battery pack needs to be recharged with 30% of the electricity (approximately 400Wh) on a daily basis. This can be accomplished within 1.5 hours using the car charging (30A DC-DC charger), and the efficiency of the charge is 55% better compared to the conventional solution.