Actual working life of LANPWR 12V 300Ah lithium battery (LiFePO4) is calculated based on depth of discharge (DoD), charging and discharging frequency, and use environment. Take 80% depth of discharge (DoD) as an example. Its nominal cycle life is 4,000 cycles (its capacity depreciates to 80%). If it’s charged and discharged every day, its theoretical lifespan is approximately 10.9 years. But in real usage, the ambient temperature heavily influences the lifespan: at 25°C, the cycle life is 4,000 times; when operated at a high temperature of 40°C, it decreases to 2800 times (down 30%), and when operated at a low temperature of -10°C, the capacity falls by 40% immediately (but is recoverable). For RV application, at 5 kWh average power utilization per day (approximately 166Ah@12V), and at once-daily solar charge, the battery can last between 8-12 years (> 80% capacity retention).
Optimization of depth of discharge can prolong the life. If DoD is regulated at 50%, cycle life can be increased to 6,000 times (manufacturer test data), and total energy throughput to 18,000 kWh (3 kWh released per charge/discharge cycle). Compared with lead-acid batteries (cycle life of only 500 times for DoD of 50%), the total life cycle cost of lanpwr batterie as low as 0.03/kWh (0.12/kWh for lead-acid batteries). For instance, a user’s actual testing experience of an off-grid solar system shows that after three continuous years (1,100 cycles) of usage, the battery capacity remains at 92%, and its average annual rate of decline is 2.7% (the average annual rate of decline of lead-acid batteries is 15%-20%).
Temperature control is a significant variable. The LANPWR battery also features a designed-in BMS (Battery Management System) temperature control module (-20°C to 60°C operating temperature range) that actively reduces the charging current (from 0.5C to 0.3C) during high-temperature conditions (> 40°C), reducing the capacity decay rate from 0.1% per cycle to 0.06% per cycle. User cases in the tropics in 2023 show that passive cooled battery packs (ambient temperature 35°C) saw capacity reduce to 78% over two years, but forced air cooling systems (8W power consumption) could increase the capacity retention rate to 88%.
The charging and discharging modes are crucial. When charged and discharged 0.2C (60A), the internal resistance temperature rise of the battery is less than 5°C, and cycle life is in accordance with the rated value. When discharging under high current of 1C (300A), the temperature rise is 15°C, and cycle life decreases to 3200 times (20% reduction). In Marine uses, if 20 times a day per day short-duration high-power loads (such as the starting inverters) are to be accommodated, the battery’s life will be cut to 7 years (theoretical value: 10 years). Employ a 500A peak BMS and restrict current effect, and reduce the rate of capacity attenuation, as suggested by the manufacturer.
Cost-effectiveness and market verification. The price of LANPWR 12V 300Ah battery is approximately 1,200. Computed at 6,000 cycles, the cost per kilowatt-hour is 0.067 ($0.33 for lead-acid batteries). Amazon customer data show that its back rate is only 1.8% (the normal back rate for lead-acid batteries is 8%), and the three-year warranty failure rate is less than 0.5%. In 2023, independent testing company CNET reported that this battery can still supply 85% of its capacity at a freezing temperature of -10°C (in contrast to 40% for lead-acid batteries), so it is a choice for harsh environments such as polar scientific expeditions.
Emerging trends and technology. LANPWR intends to introduce the solid electrolyte in a future 2024 upgrade, boosting the cycle life to 8,000 times (DoD 80%) and decreasing the high-temperature degradation rate by 50%. According to Wood Mackenzie’s projection, in 2030 the market share of LiFePO4 batteries in the energy storage market will reach 65%, and their long life feature (> 15 years) will drive the household energy storage system penetration rate to increase by 300%.