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Fifteen years of experiences

in Design & Developments

Custom Lithium ion Battery Pack

We are a full-service Battery packcustom lithium ion battery pack design, development & manufacturer, with full engineering capabilities. We have well known as large lithium ion battery pack designer as well as electric vehicle battery pack designer and developer (www.ev-info.com). At the heart of Lian Innovative custom lithium polymer battery pack is an excellent, in-depth knowledge and understanding of Lithium ion batteries, Heat transfer, Automation, Safety, Reliability and a constant drive for innovation. Our potent combination of knowledge, experience, and creativity enable us to design, manufacture and manage industry-leading lithium polymer battery pack and solutions.

We have designed different custom lithiumLithium ion battery pack polymer battery pack for various applications.  We have some rich experiences as Electric Vehicle battery manufacturer (EV), Plug-in cars battery manufacturer (PHIV) and Autonomous Underwater Vehicle battery manufacturer. Each smart lithium ion battery pack is a complete lithium ion battery system, including battery management system, thermal management equipment, the various protocol of communications and control interfaces. Our flexible technology solutions are designed to meet different capacity, voltage and amp hour requirements. A modular architecture makes our custom lithium polymer battery pack powerful and versatile. We make high voltage battery pack and large battery pack as a custom lithium polymer battery packs as well as custom lithium ion battery packs. We focus on helping our customers to the best custom lithium ion battery pack, which cost-effective, environmentally safe and beyond all of the customer specifications. Let us assist you with the design & development of your custom lithium ion battery pack. 

Custom lithium ion battery system development steps

  • Manufacturer’s independent selection of the optimum cell type
  • Modification of the battery management system(i.e. PCB, protective circuits, communication) to fit sophisticated applications, including charging technology
  • Design for highest level of safety and reliability
  • Selection of cells to  guarantee long service life

  • Host and user interface realization (Can bus, Rs485, etc.)IMG_5949
  • Application specific configuration (safety mechanisms, charging parameters)

  • DSC_00008State-of-the-art tools for mechanics and industrial design
  • Custom housings & connectors

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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.

Pack short circuit.

Cell short circuit.

Neil penetration.

Internal energy measurement.

Reverse voltage.

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Electrical integration of the Custom Lithium Ion Battery Packs

Most of the lithium-ion cells have an acceptable  life cycle img_7248(up to 10000 cycle or 10 years), but integrating them in a pack with other cells and electronics may reduce packs life cycle considerably. A big portion of modern lithium ion battery packs suffers from this problem makes user unhappy with the short life cycle. Lian innovative has introduced precise cell selection procedure and other cares that keep packs life cycle acceptable. They are as follows:

Lithium ion/Lithium polymer Cell Selection Procedure
Lithium cells like all other components have some tolerances. Tolerance in capacity, internal resistance, impedance, and other specs. Aging, working condition and manufacturing quality may change the tolerances limits considerably during the life span. It causes, aged or semi-aged battery pack cell tolerances, to be wider than what we expect. Sometimes capacities could be up to 50% different in a pack in the middle of its lifespan.
A few companies use cell selection procedure before integration of lithium ion battery packs. This procedure not only needs some expensive lab devices, and takes time, but also needs to order more cells than what it should be used in the pack. This critical selection of the cells for a battery pack not only guarantees the same specs exactly in the beginning of life cycle but also can guarantee the cells to stay in an acceptable range up to the end of the life cycle. This advanced selection procedure guarantees the final pack to keep its quality in the expected range during and up to the end of its life cycle.
Lian’s experts are in a close cooperation with the cell manufacturer continuing to improve their selection procedure to get better results from packs integration.

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Smart Lithium Ion Battery System Design  

Although lithium ion cells have a good energy to weight/volume ratios, integrating them in packs reduces their features considerably. To have an advanced custom lithium ion battery pack, system design must be advanced too. having more than eight years of different custom lithium ion battery system design, Lian innovative has introduced some very innovative system design solutions which keep these ratios at the highest level. They are as follows:

Service Plug
In high voltage custom lithium ion battery packs keeping repairmen safe from electrical shock is very important (especially in the high voltage battery pack in the electric vehicle). The best way is to use service plug which acts like a quick disconnecting switch. Lian Innovative has already equipped all of its high voltage battery packs with service plugs in its custom lithium ion battery packs.

Thermal Management of the Custom Lithium ion Battery Packs
Custom Lithium ion battery packs often need Cooling of lithium battery pack to be thermally managed in order to stay in an acceptable temperature range during charge and discharge cycles (20-25C for charge and 20- 45 C for discharge). In some cases, ambient temperature is out of the range or drained current leads the battery temperature to creep out of the acceptable range. this condition mostly happens in custom motorcycle battery and custom electric vehicle battery. In these cases, custom lithium polymer battery packs temperature needs to be controlled.
Different solutions have been introduced by other companies in system design level. Using the refrigerating cycle and circulating air between evaporator and cell body, natural convection and circulation air between conditioned water heat exchanger and cell body are experienced by different companies. These solutions have a high impact on the weight of the custom lithium ion battery pack, its structure, volume, and strength in vibration as well as its safety level and ease of maintenance.
Lian introduces innovative temperature control mechanism which uses direct contact between conditioned water heat exchanger and cell body to get lowest thermal resistance without using coolant plate, which will increase the weight and volume significantly. This innovative solution keeps high energy to weight and volume ratio and has the fastest response time for cooling and warming the cells, This innovation has been tested on some electric car battery prototype successfully.

Resistance to Shocks and Vibrations

Some custom lithium ion battery packs work in harsh environments. Heavy shocks & variable frequency vibrations appear in all state of its job. They may make some problem for custom lithium polymer battery packs including tabs electrical connection looseness. In these cases, lots of heat may produce which may lead to the unsafe battery. Lian Innovative offers a system design solution for its custom lithium ion battery packs which isolates battery structure from the battery box with a well-suited suspension system. This innovative solution is light, small and effective.