People prefer cylindrical lithium iron phosphate batteries for small energy storage power products, such as lithium battery packs under 2KWh. People will choose prismatic lithium iron phosphate batteries for medium to large energy storage power products with capacities greater than 2KWh.
1. Why do small energy storage power battery packs choose cylindrical lifepo4 batteries?
Cylindrical lifepo4 batteries include 18650, 26650 and 32650 to name a few. These three models come in many different capacity batteries and are the most common batches. There are also some less common cylindrical batteries such as the 18500 and 22650.
Benefit 1: It is easy to combine and the structure can be varied. For example, 18650 batteries, which are available in different capacities, are also the most common in the market. Its size is very flexible. We can design according to the structure requirements, such as 4S8P battery pack. We can do a 4*8 arrangement or a 16*2 arrangement, making the size very flexible.
Benefit 2: It can meet the needs of small-capacity battery packs. For example, lithium iron phosphate battery pack products require a 12.8V 2000mAh battery pack. The prismatic batteries are generally large-capacity, and there is no way to meet the requirements. At this time, you can only choose the 18650-3.2V-2000mAh battery cell of lithium iron phosphate. 4 series and 1 parallel can meet the demand.
Benefit 3: When the cylindrical battery pack is combined, the gap between the battery core and the battery core is large, and the heat dissipation is good. Cylindrical battery, coupled with the cell bracket, has a stable structure, large cell gap and better heat dissipation.
2. Why do medium and large energy storage power battery packs choose prismatic liffepo4 batteries?
Benefit 1: The prismatic battery has a large capacity, and when a large lifepo4 battery pack is combined, and the number of batteries cells used is less, and the consistency of battery pack will be better.
For example, 72V 100Ah lifepo4 battery pack, if you use 3.2V 100Ah prismatic lifepo4 battery cell, only 20S1P, 20pcs batteries are enough.If you use lifepo4 cylindrical battery 32650-6Ah batteries, you need 20S17P, and use 340pcs batteries. The consistency of the battery pack is also related to the number of cells. The more the number of cells, the worse the consistency and the worse the performance of the battery pack.
Benefit 2: The process of the battery pack is simple and the processing is convenient. Large lithium battery packs, using prismatic lifepo4 batteries cells, can use positive and negative locking stud nuts, or laser welding process, the process is simple and convenient.
However, if a cylindrical lifepo4 battery is used, it is still a method of spot welding nickel strips, which is complicated and inconvenient for processing. At present, there are also cylindrical batteries using aluminum wire welding technology, which has high cost and unsatisfactory results.