48 Volt car batteries

[dAVE]

Well, i was chatting to my dad tonight who is a journo in the auto industry and he was telling me that recently the industry had decided to change to 48 volt batteries on all new cars made after a certain period... mainly to power all the new computer equipment the cars run..

just wondering if anyone has heard about this and if u have other info.

Dave.

[dAVE]

well it was actually 42 volts.. here is more info for ppl interested.

You probably thought nothing could be simpler than an automobile battery -- 12 volts the world around. But like many other things under the hood of your car, that, too, may soon change.

That square black box next to your car's engine -- along with the electrical system it supports -- will more than triple its voltage to a whopping 42 volts, if a group of researchers from Massachusetts Institute of Technology and their industry supporters get their way. They're called the MIT/Industry Consortium on Advanced Automotive Electrical/Electronic Components and Systems.

The name is a mouthful -- but its membership is a who's who of international automobile manufacturers and their electrical components suppliers: everyone from General Motors, Ford, BMW, Daimler-Benz and Renault to Motorola, Bosch, Delphi, Siemens and Yazaki.

At a conference in Detroit this week (October 19th-21st, 1998) on transportation electronics, members of the 20-company consortium lined up solidly behind the 42-volt standard in a series of engineering presentations -- as they had done at a similar conference in Germany two weeks ago.

Why a new, higher-voltage standard for automotive electrical systems? We asked MIT research scientist Thomas Keim -- a co-director of the consortium:

"The electrical demand on the electrical system in automobiles is increasing -- because of the new and energy-requiring features which are found on new automobiles."

And what are some of these features? Some of them, says Thomas Keim, are creature comforts -- like electrically-heated seats. But many of them are more substantive, and would significantly enhance engine reliability, power and cleanliness:

"For example, electrically controlled valves. If you can actuate the valves electrically then you can vary the valve timing under computer control and maybe get an engine that produces a lot more power for its size and at the same time runs cleaner."

Electrically-actuated valves would open and close more precisely and be less mechanically cumbersome than current systems, which are driven either hydraulically or by push-rods contacting the engine's camshaft. Catalytic converters -- which chemically remove harmful pollutants from the engine's exhaust system -- function more efficiently when their precious metal catalysts are hot. Mr. Keim says electrically heating the catalysts would reduce exhaust emissions during those critical first seconds after the engine has been started.

"There are also new systems that sort of fit into the safety and comfort arena, like, for example, electrically-assisted power steering."

Experts believe electric motors would drive power steering systems much more efficiently than the current maze of hydraulic pumps and hoses that are prone to leaks and mechanical malfunctions.

So the question now becomes: why a 42 volt standard? Why not 100? Mr. Keim says the reason is safety:

"Essentially at today's 12 volt level, if you touch the positive terminal of your battery and touch the frame of the car, it's not a threatening event for the person who does that. We want to retain that."

We asked Mr. Keim whether an anticipated push toward total electric vehicles would bypass the need for higher voltage systems serving internal combustion engines:

"First off, let's recognize that even if the world goes to all electric transportation there is going to be a substantial period of transition... if the internal combustion engine goes 10 years, you're going to need 42 volts. Personally I suspect it will go longer than that. But whether it does or not we... need 42 volts."

Thomas Keim believes the 42 volt system could be implemented within five to ten years -- with more expensive, feature-laden vehicles as the first candidates.

[teka]

I read about this a few years ago, did not know if it would eventuate, it does make sense, 42v would be more efficient at providing the needed current that all the latest body computers and, ECU's, Sat Navigation etc.etc

Some of the proto typed BMW's are drawing so much current that the alternators are water cooled.

[Guest MRE]

Yep my brother is an auto sparky and he was telling me about it.

Will be great for car audio.....