ZNL Battery Co., Ltd.

中文版 ENGLISH
Products Category
News

• Handling of Cells

Contact Us

Tel: 0755-29609958
Fax: 0755-85278851
Mobile: 13702986419
E-mail: znlbattery@163.com
Add: East of 4th Floor, Building C2, 4th District, Xinhe Xinxing Industrial Zone, Fuyong Street, Baoan District, Shenzhen, Guangdong

 

Handling of Cells

Author : ZNL Date : 2012/12/30 21:52:15
 一.Handling of Cells 
 1.1 Consideration of strength of film package 
 1) Soft Aluminium foil
     Easily damaged by sharp edge parts such as pins and needles, Ni-tabs, comparing with metal-can-cased LIB.
 2) Sealed edge may be damaged by heat above 100°C, bend or fold sealed edge. 
 3)Prohibition short circuit
Never make short circuit cell. It generates very high current which causes heating of the cells and may cause electrolyte
 leakage, gassing or explosion that are very dangerous.
   The LIP tabs may be easily short-circuited by putting them on conductive surface. 
  Such outer short circuit may lead to heat generation and damage of the cell.
An appropriate circuitry with PCM shall be employed to protect accidental short circuit of the battery pack.
 4)Mechanical shock
    LIP cells have less mechanical endurance than metal-can-cased LIB.
    Falling, hitting, bending, etc. may cause degradation of LIP characteristics.
 5)Handling of tabs
    The battery tabs are not so stubborn especially for aluminum tab.
    Don’t bend tab. 
    Do not bend tabs unnecessarily.
二.Notice for Designing Battery Pack
  1. Pack toughness
Battery pack should have sufficient strength and the LIP cell inside should be protected from mechanical shocks. 
 2 .Cell fixing
    The LIP cell should be fixed to the battery pack by its large surface area.
    No cell movement in the battery pack should be allowed.
  3. Inside design
    No sharp edge components should be insides the pack containing the LIP cell.
  4 .Tab connection 
Ultrasonic welding or spot welding is recommended for LIP tab connection method.
Battery pack should be designed that shear force are not applied to the LIP tabs.
   If apply manual solder method to connect tab with PCM, below notice is very important to ensure battery performance:
The solder iron should be temperature controlled and ESD safe;
Soldering temperature should not exceed 350°C;
Soldering time should not be longer than 3s;
Soldering times should not exceed 5 times, Keep battery tab cold down before next time soldering;
Directly heat cell body is strictly prohibited, Battery may be damaged by heat above approx. 100°C
 
三.For mishaps
Battery pack should be designed not to generate heat even when leakage occurs due to mishaps.
1)  Isolate PCM (Protection Circuit Module) from leaked electrolyte as perfectly as possible. 
2)  Avoid narrow spacing between bare circuit patterns with different voltage.
 (Including around connector)
LIP battery should not have liquid from electrolyte, but in case If leaked electrolyte touch bare circuit patterns, 
higher potential terminal material may dissolve and precipitate at the lower potential terminal, and may cause short
circuit. The design of the PCM must have this covered.
 
四. Notice for Assembling Battery Pack
  Shocks, high temperature, or contacts of sharp edge components should not be allowed in battery pack assembling process.
五. Others
5.1.Cell connection
Direct soldering of wire leads or devices to the cell is strictly prohibited.
Lead tabs with pre-soldered wiring shall be spot welded to the cells.
Direct soldering may cause damage of components, such as separator and insulator, by heat generation.
5.2.Prevention of short circuit within a battery pack
 Enough insulation layers between wiring and the cells shall be used to maintain extra safety protection.
 The battery pack shall be structured with no short circuit within the battery pack, which may cause generation of 
smoke or firing.
5.3.Prohibition of disassembly 
Never disassemble the cells
The disassembling may generate internal short circuit in the cell, which may cause gassing, firing, explosion, or other
 problems.
Electrolyte is harmful
LIP battery should not have liquid from electrolyte flowing, but in case the electrolyte come into contact with the skin, 
or eyes, physicians shall flush the electrolyte immediately with fresh water and medical advice is to be sought.
5.4 Prohibition of dumping of cells into fire
Never incinerate nor dispose the cells in fire. These may cause explosion of the cells, which is very dangerous and is 
prohibited.
5.5 Prohibition of cells immersion into liquid such as water
The cells shall never be soaked with liquids such as water, seawater, drinks such as soft drinks, juices, coffee or others.
5.6 Battery cells replacement
The battery replacement shall be done only by either cells supplier or device supplier and never be done by the user.
5.7 Prohibition of use of damaged cells
    The cells might be damaged during shipping by shock. If any abnormal features of the cells are found such as 
damages in a plastic envelop of the cell, deformation of the cell package, smelling of an electrolyte, an electrolyte 
leakage and others, the cells shall never be used any more.
    The Cells with a smell of the electrolyte or a leakage shall be placed away from fire to avoid firing or explosion.
六. Storing the Batteries 
  The batteries should be stored at room temperature, charged to about 30% to 50% of capacity.We recommend that 
batteries be charged about once per half a year to prevent over discharge.
七. Other The Chemical Reaction
   Because batteries utilize a chemical reaction, battery performance will deteriorate over time even if stored for
 a long period of time without being used. In addition, if the various usage conditions such as charge, discharge, ambient
 temperature, etc. are not maintained within the specified ranges the life expectancy of the battery may be shortened or
 the device in which the battery is used may be damaged by electrolyte leakage. If the batteries cannot maintain a charge
 for long periods of time, even when they are charged correctly, this may indicate it is time to change the battery.