Your Top 5 Questions Answered On 48V Systems In The USA

To 48V or not to 48V? This is one of the questions dominating global battery and automotive sectors. With each region pursuing different regulatory and commercial frameworks, there isn’t definitive global approach for the technology. With so many questions emerging, we thought now would be a good opportunity to speak to leading experts about what 48V is, why it could bridge the gap from internal combustion engines (ICE) to full automotive electrification and whether it is a viable rollout option given the current regulatory framework in America.

1. What is 48V and what are the arguments for its implementation?

“The idea of 48V has been around for 20 years, most recently the conversation has been about using it to increase efficiency of the car – some say the savings you get efficiency-wise don’t pay back the cost of putting it in the car – but what helps the value proposition is that you are giving the car more power to do things: capture energy through braking regeneration, bringing more power to the car for features that consumers want. Some of these advanced systems would benefit from the 48V system. These advanced systems won’t be possible without a 48V size battery – so it may not be worth it just for efficiency but a tipping point could be found in allowing greater capacity.”

Phil Shaw, Global Product Manager Lead - Advanced Battery, Prod Management Microhybrid & Li-Ion, Johnson Controls International

2. Can 48V really replace 12V at a technology level?

“We may not see 12V go completely away for low power items like radios, window motors, etc.  But it may be possible to put many accessory loads on the 48V net and then use a DC-DC converter to convert the voltage, eliminating the need for a 12V battery.  The 48V battery would need to be sized for cold cranking and larger accessory loads.  As a caveat to that, there are some vehicle functions which require redundant power sources, such as autonomous driving or sailing which is turning off the engine to save fuel at high speeds.  This may not be possible for vehicles with these advanced features.  It is certainly something the industry is considering as a longer-term step (5-10 years out.)”

Angela Duren, Director of Product Management, A123 Systems

“48 Volt will be standard in addition to the 12 Volt system in specific in High Voltage Hybrid vehicles for the purpose to drive all high-power loads like climate compressor, heating and fluid pumps etc. However, I do not see any impact on the charging infrastructure.”

Edmund Erich, Independent Consultant, formerly Director of Electrification 48V/ Mild Hybrid, Delphi

3. Will the uptake of 48V systems from automotive OEMs reach 100% in their US Market Portfolio and how might this compare to the EU?

“I believe some premium OEMs will eventually get to 100% adoption of 48V architecture as a replacement to standard ICE, especially those that don't have smaller vehicles to offset their corporate averages.  These will fit alongside traditional plug in electric vehicles in the OEM portfolios.”

Angela Duren, Director of Product Management, A123 Systems

“In a first approach, US OEM´s considered implementing 110 Volts into the EE Architecture as US regulations allow this voltage in specific applications. In this case the recuperation and power boost is significantly higher and more efficient. In the EU this is difficult in terms of safety due to VDE (Association of the German Electricians) demanding a voltage limit of 60 Volt. Due to this reason EU decided to go with 48 Volt. The first high volume applications will set the technology – meaning even if there was hesitation around 48 Volt in the US it is a question of time and cost.”

Edmund Erich, Independent Consultant, formerly Director of Electrification 48V/ Mild Hybrid, Delphi

4. How can 48V vehicles be promoted to the consumder as a great alternative to the easy, but environmentally damaging ICE vehicles and the green, but curernt expensive full EVs?

“Mild hybrids using 48V batteries are generally regarded as a baby step in electrification between standard vehicles and plug-in electric vehicles.  They are fairly transparent to the consumer especially since there is little or no electric driving and no plug-in requirement.  This combined with their attractive cost per percent fuel economy saved makes them an attractive option for both OEMs and consumers"

Angela Duren, Director of Product Management, A123 Systems

How might regulation affect 48V uptake by OEMs?

“Recent developments have shown that mild hybrids could benefit from the pressure automakers flee from diesel. Current vehicles aren’t as clean as they thought they were, especially on NOX and particulates – so there’s a lot of pressure to reduce diesel use in cars. The CO2 outputs are better from diesel than petrol, and 48V could relieve the pressure on petrol CO2 emissions.”

Phil Shaw, Global Product Manager Lead - Advanced Battery, Prod Management Microhybrid & Li-Ion, Johnson Controls International

The above responses demonstrate the complex nature of the path to success for 48V in North America where complex regulatory barriers in California have meant that some OEMs are skipping the mild hybrid stage and going straight to full electrification. Elsewhere, take up has been more wholehearted with Europe leading the way on 48V systems, partially as a result of restrictions of higher voltage options. It is clear there has been a positive start and that with battery manufacturers and some large OEMs buying into the format there could yet be a bright future for 48V systems.

Are you keen to find out more about 48V batteries and systems? There are three sessions dedicated to this subject at The Battery Show and Electric and Hybrid Vehicle Technology Conference on 12-14th September in Novi, MI. The conference will feature a range of OEM, battery manufacturer and integrator ideas on how to optimize the technology.  

  • Preparing for Second Generation 48V Battery Requirements
  • Integrating 48 Voltage Systems and Components into Mild Hybrid Vehicles
  • Next Generation Powertrain Technologies