While it comes to energy density and volume efficiency, the 160Wh/kg of lifepo4 (lithium iron phosphate battery) is 3.2 times higher than lead-acid batteries (30-50Wh/kg), making the portable power station merely 12.5kg when its capacity is more than 2000Wh (the lead-acid solution of comparable capacity is 38kg). For instance, consider EcoFlow DELTA Pro. The 3.6kWh module filled with lifepo4 weighs 45×28×34cm, which is 63% smaller than the lead-acid type. However, it can support 14 devices simultaneously (with a total power of 3600W). The standard deviation of voltage fluctuation in the lead-acid system at an 1800W load is up to 0.8V (whereas lifepo4 is only 0.12V). According to Wood Mackenzie data, the lifepo4 share of global portable power stations reached 78% by 2023 mainly owing to the spatial optimization benefit brought about by its 450Wh/L volumetric energy density (120Wh/L of lead-acid).
At the safety performance level, lifepo4’s thermal runaway trigger temperature is as high as 270°C (150°C in the case of ternary lithium), and the peak in the needle-puncture test is just 80°C (up to 400°C for lead-acid). During 2022 California wildfires rescue, the Jackery 2000 Pro portable power unit powered by lifepo4 cells provided power continuously for 72 hours at the ambient temperature of 60°C under normal circumstances without any abnormality. Meanwhile, the failure rate of lead-acid equipment increased by 83% due to electrolyte boiling. The UL 2740 certifying test shows how, when lifepo4 is overcharged (1.5 times voltage), capacity loss is only 0.3% per time, while under identical conditions, the sulfation rate of lead-acid battery plates increases 5 times and life is shortened to 200 cycles.
The environmental adaptability advantage is huge. lifepo4 can still release 70% of its capacity at the low of -20°C (compared to lead-acid which is only able to release 35%), and it permits operation within the temperature range of -30°C to 60°C. The Bluetti AC200P Arctic test shows that after lifepo4 operation at a 1000W load for 4 hours in the temperature of -25°C, SOC estimation error is just ±2% (±15% error of the lead-acid plan). In efficiency in charging and discharging, lifepo4’s coulombic efficiency is 99%, with energy loss savings of 14% compared to 85% of lead-acid. At an average daily electricity consumption of 2kWh, it can release 10,220 Wh of electricity over 10 years, which equates to a saving of $1,226 in electricity charges.
From a life cycle cost point of view, although the initial investment in lifepo4 is 2.5 times that of lead-acid (for example, an example 1500Wh portable power station costs $799 while the lead-acid one is $319), its 2,000 to 5,000 times cycle life (DOD 80%) is far longer than the lead-acid’s 300 times (DOD 50%). The price of one cycle is as low as 0.04 US dollars/kWh (0.25 US dollars per lead-acid). German Consumers’ Association has calculated lifepo4 as being 62% cheaper than lead-acid if one considers the overall cost for five years’ worth of utilization, and the residual value rate remains at 45% (though lead-acid is only 5%). After Goal Zero Yeti 1500X substituted lifepo4 with lifepo4 in 2023, customers’ replacement cycle stretched from 2.3 years per replacement to 8 years per replacement, and the saved maintenance cost decreased by 74%.
In terms of fast charging and fast discharging performance, lifepo4 provides 2C fast charging to 80% within 30 minutes, 10 times the fast charging speed of 0.2C of lead-acid. The Anker PowerHouse 767 charges up to 2400Wh by lifepo4 +1200W solar input within 1.8 hours, while the lead-acid equivalent takes 9 hours. It can be observed from measured test data that the voltage drop of lifepo4 in 3C pulse discharge is only 8% (25% for lead-acid), which ensures stable operation of impact loads such as electric drills (peak power 1800W). According to the American Touring Car Association, portable power stations fueled by lifepo4 have reduced daily stress of generating power among outdoor enthusiasts by 89% and improved equipment usage to 92%.