Thermal management

Thermal management
is a battery in cold environments and high-temperature environments is essential to get a good performance and life. High-temperature lithium-ion IBM Laptop Battery to reduce the performance and life expectancy, thus limiting the scope of the vehicle driver (driving range) or performance. Thermal management system of the battery at low temperatures, heating at high temperature to heat the cooling of the battery. The corresponding thermal management cooling and heating system to increase the cost of the battery pack, weight and size. Thermal management is not only in order to maintain the IBM 02K7054 Battery temperature is below the maximum limit, but also to maintain the temperature between the single cell uniformity. To improve the battery pack Thermal equilibrium, this change requires a temperature fluctuation in a small area (for example, less than 5 ℃). Therefore, we in the battery pack design, must be based on the thermal characteristics of lithium-ion battery lithium-ion battery type selection and reasonable, and beneficial for the thermal design of the principle of equitable and reasonable battery pack cooling, thermal management system architecture. While ensuring that the system is designed with a simple structure, reliable and durable, low-cost and low-power features such as parasitic.

The same kinds of IBM ThinkPad A20 Battery at different temperatures under the conditions of heat consumption rate is relatively

The same battery at different temperatures heat rate (per 1kW h of electricity generated by the consumption of calories) is not the same, this is because the battery’s internal chemical reaction and temperature are closely linked. Shown in Figure 3, the ambient temperature on battery performance is very affected. Ambient temperature is lower, battery run-time will be more heat produced by the reaction itself. In the battery within the normal operating temperature, the ambient temperature the higher the battery self-generated heat is relatively less chemical energy consumed by the less efficient. This is because the IBM ThinkPad A20M Battery with the surrounding environment, there is heat exchange. Thermal Management should ensure that batteries in their optimum operating temperature range of environments to improve battery efficiency and to ensure that all battery operating temperature of the surrounding environment, consistency in order to ensure that all battery operation status in line.

The same type of battery comparison of different shapes

Layers are generally rectangular battery type, battery is a cylindrical winding type. They are not the same as all manner of packaging, thermal characteristics of different structures exist due to a corresponding difference. Different sizes of cylindrical and rectangular shape of the heat distribution of batteries is not the same. As the cooling surface area of different sizes, the thermal gradients within the IBM ThinkPad A21M Battery are also different. Figure 2 rectangular battery W / L big sense that there is a large cooling surface area, the internal temperature less heat better performance.

In view of different shapes of cylindrical lithium-ion battery temperature field to be more intuitive, we analyze the same type of different radius, different sizes of cylindrical battery capacity vehicles in the same state, the internal temperature field. Here are two 20Ah batteries in parallel is equivalent to a 40Ah battery.

40Ah internal battery’s internal temperature 17 ℃ and 16% of the current density uneven. The two 20Ah IBM ThinkPad 240 battery in parallel the same capacity battery, only a single cell within the 10 ℃ of temperature and 6% of the current density difference. Large-capacity battery temperature gradient larger, mainly due to the battery cooling surface area caused by a relatively smaller proportion. And experimental analysis of the two 20Ah batteries in parallel drawn more than a 40Ah battery life longer. This explains the application of some of the advantages of small-capacity battery.

Modular approach with different kinds of batteries Comparison

Battery pack is sometimes formed by a number of single cells of the battery modules. The thermal characteristics of single cells vary in their composition of battery modules, due to the number of combinations, as well as the arrangement of IBM ThinkPad 240Z battery modules packaged in different ways is also very different thermal characteristics. Therefore, we select the appropriate single battery while also considering forming a modular way, the number of single cells, batteries and packaging methods display arrangement.

We are a group of health heat a smaller force for EV God prismatic lithium-ion batteries liquid ventilation condition in the absence of the temperature field of thermal analysis simulation. Simulation Man-rechargeable batteries in the 1C discharge to the cut-off voltage of constant current state of the battery pack (module) temperature conditions.

The ideal battery pack temperature field distribution shown in Figure 4. Assuming the surface to ensure that each battery heat exchange with the outside world the same boundary conditions. post by laptop battery details.