Featured Automotive 12v vs 48v Architecture ?

Ques

Allot of golf cart moders use the prius power steering unit to add power steering to our lifted carts.

 

48V is ...

feeds the same curiosity that led to three Prius and two BMW i3-REx.

My career was fueled by my attraction to new technology: IBM mainframes; VAX/VMS; McIntosh; local area networking; tail site networks, and; wide area network monitoring.

Bob Wilson

 

@bdc101 I am a bit confused by your statement.

The subject of the thread is a look at using 48V vs 12V electrical systems in automotive circles.

Tesla is actually doing this. Why would Tesla not play a prominent role in the discussion?
We have experts taking the system apart, investigating it, and sharing their findings.

Skepticism is good and healthy. Close mindedness isn’t.

 

I suppose even the 12 volt Prius steering motors have plenty of grunt for steering a golf cart.

 

48V makes a lot of sense with the greater draw of electrical power of modern cars, with electric water pumps, power steering, and AC.

The problem which tesla appears to be solving is getting legacy parts like headlights, ignition, and starter motor swapped over (well in teslas case there isn't a starter motor or ignition ) Its going to take over a decade to transition, but it is a move in the right direction. 48V is safety so that isn't a concern.

Innovation is good, even if auto industry started talking about this innovation decades ago. Its not reinventing the wheel, but could really drop costs in non plug in hybrids as parts get used across many platforms.

 

Just a reminder that Tesla is vertically integrated. If they have no problem 'build it and take the profit' versus paying someone else a profit for less reliable delivery.

Bob Wilson

 

interesting analysis of the 48 volt architecture and other parts of the ct by the tesla team:
watch

 

Development of 48V automotive systems started years ago. Increase in the number and power draw of electric accessories lead to the concern of the 12V grid not being able to supply power. Well, they improved the efficiency of radios and such so a 12V to 48V switch wasn't required back then.

Now, the majority of ICE cars will be hybridized in the future. Mostly mild systems, and those are 48V. Just making everything 48V simplifies things and reduces some parts. It also opens up the possible use of other electric components to improve efficiency and emissions. things like electric intake chargers and catalytic converter warmers.

 

Interstate trucks have used 24V systems for a long, long time. Widespread adoption of 48V will save them a bunch of money too.

Bob Wilson

 

great, more stuff to break when the cat gets stolen

 

Yeah we talked about this, 6 years ago, when @bwilson4web started a thread about the Bosch 48V battery.
Bosch 48V battery | PriusChat
I believe this wasn't the first since even before that GM wanted to introduce 48V mild hybrids to combat the popularity of the Prius.

 

I think first BAS was 36V. Mild hybrid systems have reached a tipping point since then. A couple major automotive suppliers have their own 48V systems in addition to anything directly from an auto company. The costs had dropped to the point that they can be added to a car for under a $1000, and they are starting to become common in Europe and elsewhere fuel prices are higher. They'll follow the expansion of auto start/stop systems have taken, which seem to be on every new car here.

 

BAS was before its time. The potential good from mild hybrids to emissions and efficiency comes from mass adoption of the tech into the fleet, and BAS cost wasn't low enough for that. Toyota has been reducing the cost of their full hybrid system through the years, but current 48V mild ones are about half the cost of those now. Yes, they don't get the same improvement, but fuel costs and regulations will push them into every new ICE car relatively soon.

Stop/start systems use the same old starter motor since they are since using just a 12V battery to power it. This means harsh restarts compared to what a hybrid provides. Some just can't stand it. I only notice it when the car restarts while stop cause the battery charge dropped too much. It is less jarring when the restart happens from foot removal from the brake. One of the start/stop systems in the Malibu had a second 12V to extend engine off periods and the wear on a single battery.

I do wish it was more like what some systems elsewhere can do. They'll shut off the engine during coasts instead of waiting until fully stopped.