Power transient response is 3x faster than 12V battery.
You may wonder why does an EV need a conventional battery when there’s a 400V or 800V battery already in the vehicle to power the motors? Today the 12V or 48V batteries power all the other systems in the vehicle, but they add cost and weight and take up valuable space. Why not remove the 12V battery and use the 400 – 800V battery to power everything in the car?
The simple answer is that many automotive systems, especially safety systems, must respond quickly to sudden changes in power, and batteries historically have much better response times than DC-DC power converters. Until recently, power systems engineers have not had options for safely and reliably converting 800V or 400V down to 48V or even 12V with a fast transient response and without adding unwanted volume or weight.
Additionally new EV’s consume up to 20x more power (going from 3kW to over 50kW) than combustion engines which puts significant strain on the power delivery network, when using hard switching DC-DC converter topologies, resulting in a hefty increase in conventional power electronics that consume space, increase weight and limit range.
Because of EV power requirements, it is time to take a fresh look at how to best deliver the power needed rather than trying to retrofit the internal combustion engine (ICE) power delivery architecture. Using traditional DC-DC power converters EVs cannot handle the associated ~20x increase in power without making performance and functionality compromises which diminish their appeal. This fresh look is not a light remodeling exercise. It is a knock-down and rebuild project that needs to be explored through the lens of innovation, not convention.
The conventional progress achieved toward electrification has been driven by adding more and higher-powered batteries to cars. These batteries are heavy and large. The latest models are touting 800V batteries, but the same vehicle is also hauling a 12V and maybe even a 48V battery. With package space and weight at a premium, three batteries is inefficient and unnecessary.
Where conventional approaches add batteries, a fresh, innovative approach removes a battery, frees package space and reduces weight, all while increasing much need power transient response.