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Custom Lithium polymer battery pack safety
Today different Lithium ion battery pack safety codes have been developed to ensure lithium ion battery system works safely. Lithium ion battery pack safety has two levels. Cell safety level and Pack safety level. Almost all of rechargeable lithium ion cells have the problem with temperatures more than (130-180oC); it causes thermal runaway, toxic gas leakage, fire, and explosion. To observe lithium ion battery pack safety, the entire job is to keep them away from factors that rise their temperatures more than the thermal runaway border.
Internal or external short circuit, environment excessive heating, deep discharging and overcharging are the most common cause the temperature rising over the thermal runaway border and makes a safety problem. In modern technology, most lithium ion/lithium polymer cells can pass all of the Lithium ion safety codes except short circuits. Of course for small, low power cell, some companies introduce PTC, Pressure Release Disks, etc. in their lithium ion cells internally to manage external short circuits. However, this solution can only be used in low current rate cells, or the user may accept lots of energy losses in the cell.
For high power/high voltage, large custom lithium ion battery packs (which are used mostly as Electric Vehicle Battery Pack), it is impossible to have cells with internal current limiters. That is why it is difficult to protect them from the external short circuit. Most of the today’s advanced cells, fail to pass short circuit test required by different codes. Lian Innovative is not a cell manufacturer, but for his custom battery packs orders a customized cell to the supplier, which is much safer than normal cells, especially in short circuit test, without any energy loss. These customized cells are able to pass some cell level safety tests, which normal cells cannot pass.
In pack level, Lian lithium polymer battery packs have some redundant safety factors, including tabs insulating covers; metal shells surface passivization using insulation polymer sheets on the metallic surfaces which ensure avoiding any kind of short circuit even in the harshest accidents.
In high voltage and high energy custom lithium ion battery packs (Electric Vehicle, Etc), it’s very critical to have enough insulation resistance between cell and battery structure. Lian custom lithium ion battery packs are equipped with in-depth electrical insulation solutions that ensure a high level of insulating resistance and safety.
In most of the cells, avoiding toxic gas leakage and fire in internal short circuits test is impossible. That is why Lian Innovative custom lithium ion battery packs are designed in a way that each cell is well protected from sides, top and bottom to withstand intensive accidents or external nail penetration.
Lithium ion battery pack safety codes imply that probably leaked toxic gases must be conducted to free air far from the human’s breath, especially in Electric Cars and closed rooms. Lian’s custom lithium ion battery packs are already equipped with a rupture disk and gas outlets so that in the case of any leakage, the gas leads to the air, far from where the users are present.
Lian innovative expertise continues to improve its custom lithium polymer battery pack safety level. We targeted to reduce the risk of gas leakage or inflammation to as low as 1 in 100,000 in the packs during their life cycle.