When I tell people I'm design electric vehicle battery pack (' pack), people always ask me, what is the battery pack? What is the difference between and battery? What is the difference between car battery and mobile phone battery?

If we compare electric cars to a team, the team's operation and forward to all kinds of different backgrounds and have different ability of talented person, the battery pack is an integral part of this team, and the battery is the only one of an organ, or his heart.

Battery pack is the final purpose is to provide a variety of battery protection and support, make the battery life is longer, can deal with all kinds of extreme weather and environmental conditions.

Shell and base (Cover and Tray)

Car batteries and battery is the biggest difference is that the car had experienced the environment and the mobile phone is very different. Car will experience a variety of vibration in the operation, and from the external environment of water, soil, and the invasion of the sand. Therefore, battery shell and the base is very important.

The world of the electric car battery pack the base of the general use of aluminum alloy or stainless steel, and the upper combined with automobile chassis shell may be used in glass fiber composite materials.

Battery pack in the test passes through the three dimensional vibration, and is equivalent to more than 10 years of wind and rain (from different directions of the dust and water spray), ensure the battery internal completely without any intrusion of foreign matter, to do so.

It is worth noting that the battery pack and other automobile components have wire connection, and the wires connected to the battery pack in the middle of the part is to do so.

Temperature Management System (Thermal Management System)

Users will expect their electric cars in 365 days throughout the year all kinds of weather conditions to be able to do well. Car battery directly affect the acceleration of the car and the distance, this has to do with greatly different people watch mobile phone battery performance.

Temperature management system ensures that each single battery temperature is constant throughout the year. Extensive use of the battery under the extreme hot weather, can guarantee the timely heat dissipation, prevent battery life decreases or expansion. In extreme cold weather heavy use of batteries, battery internal warm enough, will not affect the performance and life span.

Battery cooling is to use liquid coolant flows through the bottom of the battery pack, again by thermal conductivity excellent cooling plate direct contact with single battery. Or the direct air cooling, that is, with a built-in fan.

Battery heating of the heat preservation is performed by a heater, heater of the power from the battery itself. So winter electric car distance will decrease slightly.

There is also a challenge from charging under extreme conditions. As car in full close state when charging, but temperature management system need to be in charge of automatic start, keep the battery internal temperature, that is to say, at the time of the whole car was asleep, the battery pack is still awake.

The balance of single battery (Cell Balancing)

There are many single batteries in the battery pack, there is in series and in parallel. A electric distance directly depends on the worst performance of the single battery, so keep the voltage of single battery and the rest of the quantity is also important.

One of the battery pack is called VITM (voltage current temperature module) of the device, the real-time measurement of every single battery voltage, current and temperature guarantee and through a series of resistance and the transistor to adjust for a single battery usage, instructions for temperature management system at the same time, adjust the flow rate and temperature of the coolant, battery cooling and warming.

Power electronic device (Power Electronics)

Strict sense, the power electronic devices is not part of the battery pack, but some battery manufacturers will be classified as the battery pack.

Power electronic device including the charger (charging module), regenerative braking (regenerative style) used in the inverter (makes), as well as the auxiliary energy use inside the APM (accessory power module).

Charger is power grid in the alternating current into direct current (dc) can be used directly to the battery. But with the innovation of technology, the world also gradually appear more dc charging stations, directly to the alternating current (ac) to direct current (dc) inverter made within the charging station, reduce the battery inside the necessity of this component.

In regenerative braking, however, come from the alternating current (ac) generator that can be used for battery still need to direct current (dc), in the travel of the car, the direct current from the battery that can be used for the motor must be converted into alternating current (ac), which they will use a inverter.

APM is cut the power of the battery pack to the average 12 v battery, for car interior lighting, radio and CD player, dashboard, such as air conditioning energy use. Due to the transformation in the midst of batteries and battery, you need to converter, instead of the inverter.

Dc transformer without alternating current transformer so easy, an alternating current transformer can only need one transformer, dc voltage conversion requires an inverter to convert high voltage direct current (dc) to high voltage alternating current (ac), a transformer high voltage alternating current (ac) reduce into low voltage alternating current (ac), and an inverter to convert low voltage alternating current to high voltage direct current (dc).

This process is complicated, so the industry is also using step-down converter (buck converter) or boost converter, its structure is a transistor or the diode, sensor, and the capacitor.

conclusion

The electric car's future depends on the innovation of car batteries. A new generation of battery needs a longer life expectancy, higher energy density, increase the radius of the electric car and lasting performance. Single battery leave the battery pack, as the heart is dependent on the body, every organ in supporting and auxiliary function.

We spent a long time will lead acid battery behind, start using nickel batteries, and spent a long time to popularize lithium battery. There are many different kinds of lithium battery chemistry and USES is very wide also.

As we waited for the next new before the arrival of the electrochemical technology, battery internal innovation and continuous improvement, will determine the direction of the electric vehicles in the short term, make electric cars under different environmental challenges still durable lasting.