Recently, my phone loss power easily after using for a while, so I plan to buy a new battery. I searched the battery on Taobao online store and found that the regular battery is very expensive. For example, the battery of an iPhone will cost about 86 dollars. I can’t help wondering why a small battery is so expensive? Let’s find out the answers together.
Lithium batteries are composed by batteries, power management systems, and packaging. Therefore, if you want to know the cost of lithium batteries, you need to analyze the cost of each of these three parts.
The cost of battery cell
The cell refers to a single unit containing positive and negative electrodes. The cell, which accounts for 80% of the cost of the lithium battery, is the most expensive part.
Statistics show that among the hundreds of battery factories in China, their product quality varies greatly. At present, the price of the battery cell on the market is generally 0.17 to 0.19 dollar/WH if we take lithium iron phosphate battery for automobile as an example.
The cost of battery management system (BMS)
The cost of BMS accounts for about 10% of the lithium battery. BMS is a system to manage, maintain, and monitor each battery cell. This is how the BMS prevents the battery from being overcharged and over-discharged, thus prolong its life cycle.
There are many manufacturers producing BMS in China, but the quality and price vary greatly as well. Let’s take BMS of 48 V used in forklift as an example, the price is generally between $201.68 and $360.15.
However, some suppliers who lack safety awareness will spend about $28.81 on protection board to save costs. But it only has a part of the function, serving as the voltage and time potentiometer.
The cost of pack system
The pack system contains functional components, wiring harness, structural parts and other related components. In many lithium batteries, internal welding parts crack sometimes. Even some large pack factories can hardly avoid this problem. Therefore, the quality of the packing process and the joints are the focus of frequent quality problems.
Functional components of various qualities also see various pricing levels. Let’s take relays as an example, the relays cost about $93.63 per piece if it’s used by manufacturers that focus on safety and quality. But some cheap relays only cost $28.8 per piece. The products are so cheap that you can’t expect long-term safety and performance stability.
In the packaging process, large manufacturers adopt large-scale laser welding processes to ensure product safety and performance stability. However, there are some small-scale pack assembly plants that use simple copper strips. They adopt this soft connections to reduce costs. The cost gap for this part is about $288.
The cost of the finished battery
With what’s said, we take lithium iron phosphate of 48v/ 400ah (19.2 degrees electric/19200wh) as an example.
Assuming that we consider about $3,745.59 per group of the purchase cost of class A battery cell, plus the BMS, the functional components and the pack system, as well as the company’s management costs, research and development expenses, and reasonable profits and other factors. The final market price is generally 40 to 50 thousand yuan per group, or about 0.31 to 0.36 dollar/WH. This is a relatively reasonable price range.
For class B or lower quality of the battery cell, the purchase cost is about $2,016.85 per group. Then, the market price is about 25 to 30 thousand yuan per group, or 0.17 to 0.22 dollar/wh.
The above is just what we’ve experience as of March 2018. If you have any question, please feel free to contact us. We’d be glad to hear from you.