Electronic products have been around in modern societies for nearly thirty years, especially consumer electronic products have largely grown for the past five years, which increased the demand for battery’s energy density. Currently, rechargeable batteries, such as lead-acid battery, Ni-MH Battery, and lithium battery, are commonly adopted in the market. Ni-MH battery and lithium battery (LiCo/NMC) are widely adopted in various kinds of consumer products, while Lead-acid battery and high power Lithium-ion Battery (NMC/ Li-Mn/ LFP/LFPO) are more used in power tool products.
Historically, lead-acid battery has lasted for over a century since its introduction in 1859. It has now evolved to valve-regulated lead-acid battery at this stage. Its application varies from automotive application to power back-up application. With increasing demand for battery capability, there is a great challenge for lithium battery to replace lead-acid battery.
LFP/LFPO Battery’s Advantages
With improved technology development of power lithium battery, people start to see lithium battery as an alternative option to lead-acid battery. Although the advantages of lead-acid battery are mature technology and low price, many problems still need to be solved, including low energy density and short life time that increases maintenance frequency. Therefore, Li-Mn battery, NMC battery, and LFP/LFPO battery are selected to obtain better quality on high energy density and convenience. Li-Mn and NMC batteries have better performance in energy density while LFP/LFPO batteries, though have lower energy density than Li-Mn and NMC batteries, attain the following advantages
Long lifespan is the greatest advantage of LFP/LFPO battery. Low depth of discharge is the feature of lead-acid batteries which are simply designed with no power management system. Although lead-acid batteries are cheaper, they are merely charged for 300~500 times. However, in general lithium batteries can be recharged up for 500~700 times, and LFP/LFPO battery can be charged up to 2000 times.
Since the development of lead-acid battery has been over a century, it is widely adopted in our daily life, including vehicle storage battery, pedelec, and power back-up system. However, lead-acid battery has lower energy density and shorter life time, compared with that of lithium battery. Additionally, LFP/LFPO battery’s working voltage is 3.2V, while LiCo and NMC batteries are 3.7V. Therefore, a 12V lead-acid battery can be replaced with connection of four LFP/LFPO batteries. Due to high working voltage of LiCo and Li-Mn batteries, it is hard to match voltage connection.
New Business Opportunity in Standalone Photovoltaic Lighting System
After Japanese earthquake, demands for energy-saving products such as LED light bulbs and inverter air conditioners have largely increased. On the other hand, the damaged infrastructure in Japan has also increased the demand for standalone photovoltaic lighting system as they require no grid connection. In fact, the major target market of standalone photovoltaic lighting system is focused on the areas with fewer infrastructures, like Southern America, Africa, or developing countries.
In addition, standalone photovoltaic lighting system covers lighting module, solar energy module, and storage system. Currently, development of lighting and solar energy modules has become relatively mature. But due to various kinds of battery specifications, battery choice is a crucial factor to system construction. For example, 1800 Wp solar cell is required for a 3000 lm lighting system. But there is more to consider for battery storage system; if average operating time is ten hours per day in an environment lack of sunlight, high battery storage capacity is required. This is why lithium battery development is an important puzzle to fulfill this market demand in the future.
Standalone Photovoltaic Lighting System