Unique battery management technology
Electroengine has developed a unique battery management technology. Each cell is checked individually and can therefore be charged and discharged individually. Once the voltage has reached the required level in each individual cell the charging is discontinued. As the battery pack is used up the system manages the battery so that all the cells reach the lower level of voltage at the same time, which means that the maximum amount if energy can be extracted from the battery pack without risking damage to individual cells.
All this, combined with a very effective battery solution in terms of energy/weight, means that only approximately 1-2 kg of battery is required per kilometre driven. Modern battery technology usually requires approximately 2-4 kg of battery per kilometre. This results in the battery costs being reduced dramatically in a True Electric car.
Electroengine is also currently evaluating battery cells with an even higher energy content, which should make much greater ranges possible in the near future than can be achieved with existing battery technology.
With current technology, there is a risk that a whole battery pack, which can cost more than 100,000 kronor, may fail if just one of perhaps 5,000 cells is destroyed. Great efforts are therefore usually made to match the cells in a battery pack so that they are all as similar to each other as possible in terms of characteristics. This is a time-consuming and therefore very costly process. No such matching is required with True Electric, as individual cells can simply be replaced.
This offers a number of advantages:
- Fewer cells are required and these can be used to easily build a battery pack at a competitive price and with a lower total weight – which in turn means that more batteries can be used and the car’s range can be increased.
- Better protection against battery malfunctions. If a battery cell fails it can be easily identified and replaced, which also results in a longer battery pack life. The vehicle can still be driven even if one or more cells break.
- Vehicles can travel approximately 10-30 percent farther on one charge with True Electric’s battery management than is the case with conventional electric propulsion technology, as each individual cell can be charged and discharged to the maximum in terms of its individual capacity.
Cheaper and better batteries
High performance lithium batteries can still not be found in many electric cars. This is partly because of their price, as well as uncertainty about how long they last. Such batteries usually need to be replaced in mobile phones and laptop computers every 3-4 years. A battery pack for an electric car must work longer than that to make the cost of the battery reasonable.
Lithium batteries have, until now, mainly been constructed with cobalt oxide in the cathodes, which has made them susceptible to overheating and short circuits. Cobalt is also an expensive material due to its scarcity. Battery research is now looking at other cathode materials, such as iron phosphate. Such batteries are thermally stable, are less susceptible to short circuits and can also be recharged many more times without losing capacity. They are also much cheaper to produce.
It is this type of battery (i.e. lithium iron phosphate) that forms the first generation of the True Electric system. These batteries do not contain any heavy metals or corrosive substances and are neither explosive nor flammable. In the future, new generations of battery technology that are developed can be implemented very simply in the system.
