Emergency lights play a vital role in modern life. Whether in homes, commercial buildings, or public facilities, emergency lights provide illumination and indicate exit routes when regular power fails, reducing panic and chaos in emergencies and ensuring the safe evacuation of people from buildings. However, the choice of batteries is crucial for ensuring that emergency lights function consistently. Emergency light batteries not only directly affect the performance and reliability of the equipment but are also closely related to long-term operating costs, i.e., cost-effectiveness.
What is cost-effectiveness?
Cost-effectiveness is used to evaluate the economic rationality and performance of an investment, decision, or project. Simply put, cost-effectiveness refers to the benefits or gains obtained while incurring a certain cost. Battery cost-effectiveness considers not only the initial purchase cost but also factors such as lifespan, maintenance costs, charging efficiency, and environmental friendliness. A cost-effective battery should not only have advantages in initial investment but also demonstrate low cost, high efficiency, and sustainability in long-term use.
Next, we will compare the most commonly used batteries for emergency lights on the market: nickel-metal hydride batteries, nickel-metal hydride batteries, and lithium iron phosphate batteries to see which battery is more cost-effective.
Nickel-ion batteries
In the past, nickel-cadmium batteries were the most common type of battery used in emergency lights, due to their durability and ability to operate in harsh environments. However, nickel-cadmium batteries have low energy density, are larger than other types of batteries, and contain cadmium, a highly toxic metal that is one of the six substances prohibited by the EU RoHS Directive. Although their use in emergency light batteries is temporarily exempted, their disposal and recycling still present challenges.
Nickel-metal hydride batteries
Nickel-metal hydride (NiMH) batteries have 30% higher energy density than nickel-cadmium (NiClear) batteries, meaning they store more energy per unit volume or mass. NiMH batteries are more resistant to overcharging and over-discharging, do not contain heavy metals, and have no serious environmental impact. However, compared to NiClear batteries, NiMH batteries have poorer durability under harsh environmental conditions, poor high-temperature charging performance, a higher self-discharge rate, and higher material costs.
Lithium iron phosphate batteries
With the continuous development of lithium battery technology, emergency light batteries have a new option—lithium iron phosphate (LFP) batteries. LFP batteries boast high energy density, stable chemical properties, high temperature resistance, long lifespan (more than twice that of nickel-metal hydride (NiMH) batteries), and are free of heavy metals and harmful substances, making them more environmentally friendly. Although LFP batteries have a higher procurement cost, their overall benefits are superior.
Furthermore, emergency light batteries need to be fully charged during normal power supply to cope with emergencies. Therefore, the charging method directly affects energy consumption and lifespan. Nickel-cadmium and nickel-metal hydride batteries, under high charge conditions, primarily consume energy through internal oxygen cycling, leading to energy waste and shortened lifespan. In contrast, lithium iron phosphate batteries have low internal resistance and low self-discharge rate; by equipping them with a smart BMS and long float charging technology, energy consumption can be minimized while maintaining a full charge.
In summary, compared to nickel-metal hydride (NiMH) and nickel-phosphate (LiFePO4) batteries, LiFePO4 batteries offer a longer lifespan and a more efficient charging method, resulting in lower maintenance costs, reduced recycling requirements, and lower replacement costs. Over time, LiFePO4 batteries will provide substantial returns, making them the most cost-effective battery option.
At Juda, we are committed to the research and development and production of iron phosphate batteries. Our emergency light batteries are characterized by high temperature resistance (can operate in high-temperature environments up to 75℃), automatic hibernation (can still be used after being stored for 580 days), long lifespan (10-year calendar lifespan), and compliance with international certification standards (IEC 60598-2-22:2022, IEC 62620, IEC 62133 AS 2293.3, UN 38.3).
