Electronic Components Datasheet Search |
|
IEC62281 Datasheet(PDF) 3 Page - Littelfuse |
|
IEC62281 Datasheet(HTML) 3 Page - Littelfuse |
3 / 8 page 3 c n I , e s u fl e tt i L 12 0 2 © 1. Short-Circuit tests and Forced Discharge tests: These tests are conducted by discharging the battery with a low resistance load and then allowing the battery to protect itself or fail by re or explosion; the latter being a test failure. A test pass is when battery returns to a safe temperature. Tests are done at room temperature and elevated temperatures. 2. Abnormal Charging test, Overcharging test, High Charging Rate test: These tests are conducted by subjecting the battery pack to several times more than the normal charging current or charging at an abnormally fast rate. When there is a non-resettable over-current device present, the test is repeated at a current below which the device activates. 3. Heating and Temperature Cycling tests. These tests are conducted by raising and cycling the battery pack to high temperature and then checking to see if the pack responds safely. Fire, explosion, and venting would be considered failures. The purpose of the safety standards is to ensure the battery pack and cells have protection mechanisms designed into the overall system to prevent rapid thermal runaway, re, explosion, rupture, venting, or even gas bloating of the battery packs. All of these events can create a hazard to the user or any equip- ment used with the battery pack. Typical Li-ion and lithium-polymer battery packs have several levels of protection in order to meet the required safety standards and to protect the user and equipment from battery failure hazards. In addition to internal cell level protection, external protection solutions are added to provide further safety mea- sures. Some battery packs will use what is called a Battery Management Unit (BMU), which is a small print circuit board with several protection components (see Figure 2). The BMU will have a central processing device, which is usually an IC that controls the battery charge and monitors the pack for unsafe conditions. The battery controller IC controls two FETs, which act as the charge and discharge switches. The battery IC will turn these FETs off as the primary way to shut down the battery pack. The IC will use thermistors and temperature cut-outs (TCO) to sense temperature, current sense resistors to monitor current, gas gauges to monitor gas buildup, and fuel gauges to monitor charge. Upon any unsafe condition, the IC will turn the FETs off to shut down the pack and stop the fault event. Because the Li-ion chemistry is so dangerous in certain conditions, there must be a secondary method for protection. This secondary protector can be a PPTC (polymeric positive temperature coefcient) resettable fuse, thermal fuse, or a controllable battery protector (see Figure 3). Figure 2. A typical Battery Management Unit (BMU) design Figure 3. A secondary method of battery protection Application Note: Use of Low Resistivity Surface Mount PPTC in Li-ion Polymer Battery Packs Control IC Battery Pack Discharge Charge Switch Switch + – SMD PTC Battery Cell Battery cell PCM |
Similar Part No. - IEC62281 |
|
Similar Description - IEC62281 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |