Hybrid vehicles were once thought to be the next logical step in the evolution toward full EVs. Today, consumers thinking about going electric are more likely to buy an all-electric vehicle than a hybrid model, and sales of all-electric vehicles have been running twice those of plug-in hybrids, according to Boston Consulting Group.
That shift has major architectural implications for OEMs, because all-electric vehicles have to deliver power not only to drive the wheels of the vehicle, but also to run all of the other devices that in a gas-powered or hybrid vehicle would be powered by the engine. Instead of taking a gas-powered vehicle and bolting on an electrification component, an all-electric vehicle means redesigning from the ground up.
Battery technology is improving very quickly, so OEMs are installing new batteries in their all-electric vehicles that can hold more charge for greater range. While a typical vehicle battery previously would have supplied about 50 kilowatt-hours of power, future battery capacities are rising toward 200 kWh as energy density increases and battery costs rapidly decrease.
While the increased capacity is a boon to the consumer to eliminate range anxiety and provide increased acceleration, charging the battery in a reasonable time frame becomes a challenge. OEMs can reduce these charging times by increasing the current, increasing the voltage, or both.
Increasing the voltage
Higher currents require larger cables in the vehicle, adding cost, space and weight. There is limited space in a vehicle chassis to begin with, and the increased size and weight associated with high-power electrical distribution system creates even bigger challenges for vehicle packaging design. Therefore, manufacturers are also looking at increasing voltage as an option.
For example, in a simplified comparison, a typical EV with a 100 kWh battery pack charging at 250A and 400V would take approximately 48 minutes to charge to 80 percent. With an 800V system, this time could be cut in half.
Higher-voltage systems enable faster charging, less heat, and thinner wiring or busbars. Increasing voltage means ensuring that the components are built with safe distances between the terminals and with safe distances between the terminals and ground/shield. Designs must take into account both clearance distance over the air and creepage distance over the surface — to prevent arcing and to prevent small currents going from one terminal to the other.
Aptiv’s broad portfolio of high-voltage interconnect technology is designed to handle 1,000 volts, so OEMs can install the latest battery technology today with the assurance that it will meet their needs for years to come.
Learn more about the major considerations related to high-voltage interconnects in our recent white paper.