26650 Lifepo4 Battery Pack

Is 26650 a LiFePO4?

26650 lithium ion battery, diameter 26MM, length (height) 65MM. Commonly known as lithium-ion batteries, common 26650 lithium-ion batteries use nickel-cobalt-manganese (ternary) and lithium iron phosphate as positive electrode materials. The voltage of the ternary 26650 lithium-ion battery is 3.6/3.7V, and the voltage of lithium iron phosphate is 3.2V.

26650 lithium-ion batteries are often used in large power tools, lighting equipment, energy storage equipment, electric vehicles, UPS backup power, medical equipment and special equipment and other fields.

Which is better LiFePO4 vs lithium ion battery?

Lithium battery is a kind of lithium battery with lithium iron phosphate battery as the positive electrode material of the battery. The key cathode materials of lithium batteries are lithium cobalt oxide batteries, lithium manganate batteries, lithium nickel oxides, ternary materials, lithium iron phosphate batteries, etc. Lithium iron phosphate battery of secondary battery, the key development prospect at this stage is lithium battery, which has great advantages compared with NI-H and Ni-Cd rechargeable batteries. Lithium battery is made from lithium metal material or lithium aluminum alloy as the positive electrode material of the battery in a non-hydroelectric power generation solution. The physical properties of lithium metal materials are very bright, so there are strict regulations on its production, processing, storage, application and ecological environment protection.

When the rechargeable lithium iron phosphate battery is overcharged to 100%, it is not easy to cause an explosion accident; when the lithium battery reaches a certain standard value, vapor will be produced for precipitation. Lithium battery is the typical working voltage of a single lithium iron phosphate battery. The lithium iron phosphate battery is resistant to overcharge and overdischarge, and overdischarge can repair more than 80% of its characteristics in a short time. Over-discharge of lithium batteries will cause irreversible damage. The lithium iron phosphate battery can be charged and discharged with a large current, and it can be charged and discharged beyond 10C20C, while the lithium battery can only be charged and discharged at 3~4C.

There is no fire and no explosion during puncture, and no lithium battery will explode. However, the specific energy of lithium iron phosphate batteries is not as high as that of lithium batteries. The working voltage difference is smaller. Because of its large charge and discharge characteristics, it has key applications in pure electric vehicles, aviation models, etc. Large-capacity lithium batteries are mainly used in civilian industries.

In addition, using lithium iron phosphate battery (LiFePO4) as the positive electrode material of the battery and copper as the raw material of the rechargeable battery not only reduces the cost, but also improves the safety factor. The P-O bond in the crystallization of lithium iron phosphate battery is very stable and not easy to dissolve. Even under high temperature or overcharge standard, it will not cause heat or structure collapse, which can be trusted.

What is the lifespan of a LiFePO4 battery?

Ultra-long life, the cycle life of long-life lead-acid batteries is about 300 times, and the maximum is 500 times, while the lithium iron phosphate power battery produced by Guangzhou Fengjiang Battery New Technology Co., Ltd. has a cycle life of more than 2,000 times. Standard charging (5 hours rate) use, can reach 2000 times. The lead-acid battery of the same quality is “new half year, old half year, maintenance and maintenance for half a year”, which is 1-1.5 years at most, while lithium iron phosphate battery will reach 7-8 years when used under the same conditions. Taken together, the price-performance ratio will be more than 4 times that of lead-acid batteries.

Can you overcharge LiFePO4 battery?

When the battery is overcharged, a large amount of Li+ is released, and the generated FePO4 increases, causing a large polarization resistance and polarization potential, and the voltage of the battery rises rapidly; too much lithium is released, and the binder on the pole piece is destroyed, causing The positive electrode paste is detached from the current collector, and there is a large area of paste loss, and the prolapsed Li gathers on the negative electrode, forming white dots.

How many times can a LiFePO4 battery be recharged?

Regular manufacturers can charge and discharge batteries at least 500 times, and the capacity is maintained at more than 80% of the initial capacity. If charged and discharged once a day, batteries can be used for two years.

Can LiFePO4 batteries be fully discharged?

LiFePO4 batteries can be continually discharged to 100% DOD and there is no long-term effect. However, we recommend you only discharge down to 80% to maintain battery life.

How do I revive my LiFePO4 battery?

The lithium iron phosphate battery can recover from overdischarge. When the battery is discharged, lithium ions are deintercalated from the graphite crystal, enter the electrolyte, and then pass through the separator, migrate to the surface of the lithium iron phosphate crystal through the electrolyte, and then re-insert into the phosphoric acid. within the iron-lithium lattice.

To know whether the lithium iron phosphate battery pack is overcharged or overdischarged, it is necessary to understand its charge and discharge calculation method.

Lithium iron phosphate battery pack charge and discharge calculation method Charging: The charging process is a process of filling a bucket with water, and this process is a period of time. The bigger the faucet, the faster it fills up. Similarly, charging the battery depends on the charging current. The higher the current, the shorter the charging time!

The charging current is 20A, that is, the full charge time is 5 hours; the charging time is obtained by dividing the capacity of the battery pack by the current.

Discharge assumption: the power of the load end is 500W, namely: 500W (load end power) / 48V (rated voltage) = 10.42A (current) 100AH ​​(battery capacity) / 10.42A (current) = 9.6 hours (working time) overcharge and overdischarge It is an operation behavior that exceeds the original capacitance. Overcharge and overdischarge will damage the lithium iron phosphate battery, causing battery damage, which is irreversible.

Overcharge will lead to lithium dendrites, and overdischarge will lead to copper dendrites, which will cause problems such as short circuit and failure of lithium batteries; therefore, lithium batteries require shallow charging and shallow discharging. At present, in the process of using lithium batteries, it is necessary to have a protection circuit as much as possible, so as to ensure safety. At the same time, lithium iron phosphate battery is a relatively safe one among lithium batteries.

Do LiFePO4 batteries need a float charge?

A lithium battery does not need a float charge like lead acid. In long-term storage applications, a lithium battery should not be stored at 100% SOC, and therefore can be maintained with a full cycle (charged and discharged) once every 6 – 12 months and then storage charged to only 50% SoC.

Can LiFePO4 batteries get wet?

Do not expose the battery to water or moisture. Water can corrode or damage the internal battery safety devices and cause the battery to overheat, ignite, rupture or leak.

Do LiFePO4 batteries get hot?

The research shows that under the condition of 1C-rate overcharge, the starting temperature of the LiFePO4/C battery thermal runaway is about 116 °C – 131 °C, and its temperature rise rate of thermal runaway is about 3.01 °C/s – 5.82 °C/s.

What voltage should a LiFePO4 battery be?

Individual LiFePO4 cells have a nominal voltage of 3.2 volts. They are fully charged at 3.65 volts and fully discharged at 2.5 volts. You can buy individual LiFePO4 battery cells online. They’re best used for making your own lithium batteries.

Will LiFePO4 catch fire?

Lithium iron phosphate batteries will not explode and catch fire under normal circumstances. The safety of lithium iron phosphate batteries is relatively high in normal use, but nothing is absolute, and it will still be dangerous in some extreme cases. This has a lot to do with the material selection, ratio, process and later use of each company.

First, lithium iron phosphate batteries overheat due to electrical shorts, rapid discharge, overcharging, manufacturing defects, poor design, or mechanical damage. Overheating can lead to a “thermal runaway” process, an exothermic reaction inside the battery that causes the battery’s internal temperature and pressure to rise at a rapid rate, wasting energy. Once a battery cell goes into thermal runaway, it generates enough heat that the adjacent battery cells also go into thermal runaway. As each battery cell takes its turn to rupture, releasing its contents, a fire that burns repeatedly is created. This causes the flammable electrolyte in the battery to leak, and if a single-use lithium battery is used, it also releases flammable lithium metal.

Another is caused by the external environment, such as the external environment temperature is too high, or the temperature control system fails, and the heat cannot be dissipated due to excessive heat, which will also lead to fire.

We know that whether it is driving, charging, or collision, it may cause the lithium iron phosphate battery to catch fire. Although these three are in different states, they have one thing in common, that is, the heat loss of the battery is caused, and the overheating will inevitably cause a fire.

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