LiFePO4 battery pack

Short Description:

Padre can produce OEM LiFePO4 battery packs(lithium iron phosphate battery) with high stability, safety and high discharge rate, according to different requirements for global customers.

Description

LiFePO4 battery pack is designed mainly for many applications that requires different voltages and capacity, most battery packs are customized according to detailed requirements. because of the lithium iron phosphate material new features such as very long cycle life, safe and stable high temperature performance, environmental friendly,fast charge, low self-discharge rate, no memory effects, the LiFePO4 battery pack is widely used for many fields to replace traditional lead acid battery,NiMh and NiCd battery.

Padre can OEM/ODM different LiFePO4 battery packs with different voltage(3V,12V,24V,36V,48V,144V and so on), capacity(1Ah to 1000Ah),case(plastic and metal ones), BMS(specially customized design and standard offer) for different applications.

There are three parts that made up a complete Padre LiFePO4 battery pack:

1-LiFePO4 cells

For a rechargeable battery pack, the first thing needs to pay attention to is the cells consistency. because the cells will be assembled together in series or parallels, they must have very good consistency to ensure the whole battery pack nice performance, it has great influence on the battery discharge capacity, work voltage, work time, cycle life and stability.

Padre has strict process on battery cell matching based on below aspects to ensure great cells consistency:

a-Voltage conformity, ≤10mv

b-Capacity conformity ≤1%

c-Impedance conformity ≤4mΩ

d-Charge conformity≤1%

e-Self discharge conformity≤1%

f-Discharge stage conformity≤1%

g-Charge C rate conformity≤1%

2-PCM/BMS(Battery management system)

BMS is a vital key important part for a good lithium battery pack, closely related to the battery performance and safety.Padre insist on independent R&D of advanced BMS.

a -The BMS protection control circuit has unique intelligent protective functions,such as secondary over current protection, third grade protection for short circuit,restraining high voltage pulse and contrary electromotive force absorbed, temperature sensor system,over voltage protection and auto reactivation by releasing protection in addition of generic functions , over charge and discharge protection and auto balance and so on.

b-We use US new special CPU for first-rate power lithium ion battery as main control CMOS chip, Padre BMS/PCM also includes testing port for battery data input and output, set the protection parameters to fit different kinds of batteries and satisfy clients for various requirements.

c-With low MOS impedance of 0.3mΩ, Big current can be used for the last switch for charge and discharge protection by multi- tubes in parallel, which helps releasing the battery capacity maximally and enhancing the safety of batteries efficiently , lowers the battery internal temperature.

3- Case and assembly.

We offer very flexible choices on the battery case and parts involved, plastic case, metal case are available,different connectors, plugs, ports design, and data display are within our ability, we can meet most of requirements from clients.

Padre LiFePO4 battery pack takes standard safe isolating configuration that cells and case keep distance with each other.In order to improve the performance of resisting vibration and impact , the cells are separated with partition to weaken the intensity of vibration, and ends of leads are enveloped with glue.This design makes it more convenient for products testing and battery quality improvement. and in long term this benefits mass-production and maintenance of batteries.

The whole pack case is made up of high strength and anti-burning board that can protect battery from impact of outside force to enhance, dissipate the heat of cells effectively and prolong the use life of batteries.

4-Padre LiFePO4 battery pack safety performance test

No.	Test item	Test condition and method	Requirements	Result
1	pounded resistances	full charged、25±2,full charged、25℃±2℃，10kg heavy hammer、drop down from 1 m high sky ,hit the battery	No explosion no fire	pass
2	thermal shock	30minfull charged,130℃±2℃,bake for 30 minutes	No explosion no fire	pass
3	over-charged resistances	full charged,25℃±2℃,as 2C5A charge battery till twice of upper limited voltage or cooling of battery appearance	No explosion no fire	pass
4	over discharged	full charged,25℃±2℃,0.2C5A discharge till 0V of each cell	No explosion no fire	pass
5	short circuit resistances	10℃full charged,25℃±2℃,use 0.1Ω resistance connect the positive and negative till battery temperature fall down 10℃compare to highest temperature	No explosion no fire	pass
6	storage under high temperature	48hfull charged, set in 85℃±2℃high-temperature cabinet for 48h	leakage free, do not smoke, explode or catch fire	pass
7	high temperature	mantel the battery with special metal gauze, till it exploded or destroyed.	none parts of exploded battery went through the grille, none parts stick out of grille	pass
8	puncture resistances	full charged,25℃±2℃，impale any of single battery of pack by 3mm diameter draw point	No explosion no fire	pass
9	pressed resistances	full charged,25℃±2℃,push two max appearance coverage, stop when pressure reach 13Kn	No explosion no fire	pass
10	low voltage resistances	Put the battery pack in vacuum tank, evacuate till 11.6kPa or lower, keep it in 25℃±2℃for 360min	leakage free, do not smoke, explode or catch fire	pass
11	constant muggy	set under 60℃±2℃after full charged、humidity is 90%-95% constant temperature humidity chamber for 12h, then take out	no deformation、corrosion、smoke、explode, capacity no less than 90% of standard	pass
12	vibrate resistances	have the test from X,Y,Z three directions. Scanning frequency vibration for 90-100min from 10Hz-55Hz, rate as 1oct/min, displacement as0.8mm	no damage、weeping、smoke or explode，work well	pass
13	impact resistances	bear the impact from X,Y,Z three directions. Acceleration no less than 75g in the first 3ms, peak acceleration reach 125g-175g,impact times are 1000±10	no damage、weeping、smoke or explode，work well	pass
14	temperature circulation	set in 70℃±2℃high-temperature cabinet for 12h;then set in -40℃±2℃keep for 12h. Repeat above for 9 times, set in room temperature and discharge	No weeping、smoke、explode or catch fire; battery pack appearance and quality have no obvious damage, capacity no less than 70% of initial	pass
15	insulation resistances	insulation resistance tester DC 500V test the battery positive ,negative and metal back	No explosion no fire	pass
16	water logging resistances	Put the battery pack into water, keep charging for 7d, drain the water, keep charging for 24h	leakage free, do not smoke, explode or catch fire	pass
17	drop down from the high place	Drop the 95kg battery pack from 55m height, impact the steel plate as 115km/h, instant impact force could reach 3.1ton	do not smoke、explode or catch fire	pass