How come..............

Dr.Jeff said:
That's how I feel about electric cars in general. People seem to forget that they are merely transferring the burden on the ecology from one source to another - the "grid" in this case. In many areas the generation of electrical power has a huge environmental impact.



Back in the 70's-80's the air-cooled VW scene was HUGE in Orange County (SoCal). It was said there were more VW's in O.C. than the rest of the world combined. That might have been an exaggeration, but it illustrates the point (I think there actually was more Porsche cars in O.C. than everywhere else combined though). The gas burning heaters were a highly sought after accessory to try and make one's Bug stand out from all the rest at the shows. They commanded a very high price, despite there being absolutely no need for it in SoCal. However the stock heating system (passing air around the exhaust manifolds into the passenger compartment) was not without its own dangers; frequently there would be a small exhaust leak that entered the heating air stream, filling the passenger compartment with a funny smell.



Likewise for electric air conditioners. Which might explain why I often see Teslas on the back of flatbed tow trucks halfway between Vegas and LA; the extra electrical load depletes the energy store pretty quickly.
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You may be getting the energy from another source but an electric car can be over 50% cleaner than a modern ICE car even it the electricity is generated by a coal powered plant.
An electric motor is as high as 90% efficient compared to a modern ICE that is about 70% efficient throwing the other 30% into the atmosphere in the form of heat and carbon dioxide.

The electric A/C's are probably pulling close to the same amps as an electric heater, then combine that with higher rates of speed and it eats the amps.
Do they have signs up saying no electricity for next 100 miles yet?
 
dragonsgate said:
Do they have signs up saying no electricity for next 100 miles yet?
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There used to be signs saying no water for the next XXX miles. That was back when cars had more primitive cooling systems and overheating in the desert was common. Remember the "desert bag" that you could hang in front of your radiator?
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The big worry I have about the big conversion to electric cars is when everyone comes home from work in the evening and plugs in their cars to charge them overnight. I seriously doubt the current electric grid will be able to handle the load and brownouts or worse will ensue. Maybe pedal cars are the future.
 
carl said:
The big worry I have about the big conversion to electric cars is when everyone comes home from work in the evening and plugs in their cars to charge them overnight. I seriously doubt the current electric grid will be able to handle the load and brownouts or worse will ensue. Maybe pedal cars are the future.
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In some Euro cities pedal transportation in the form of bicycles is the norm.
Don't worry about people plugging in their cars when they come home causing brown-outs. They will plug their hydrogen powered cars in and power their homes. Battery power it seems to me is at a dead end. Only politics keep it alive.
OK, now off my soap box...
 
The question I've asked myself for 40 years is "How come we are still on these antiquated 12 volt electrical systems?" Very old cars had only 6 volts and some clever folks decided to double it to 12 so we could actually see where we are going at night. I wish that bunch were still around. Because at 12 volts any power-hungry device, whether a starter, space heater or even a headlight, is going to draw a huge amperage because (instantaneous) power = voltage x current. A 120 volt car electrical system would need roughly 60 amps to start your car, not 600! All the complicated relays and Brown Wire Mod etc. are just compensating for high current draw because of a downright wimpy electrical system. Think of how much weight and cost could be saved if we didn't use all those copper cables everywhere. Even 48 volts would drop the current 75%. All of the wiring could be made a much lighter gauge than we use today.

I also have longed for the days of inexpensive sports cars. But the current situation isn't that bad really. "Normal" people alive today don't even like sports cars. As hard as it is for me to grasp, most people want to sit three feet off the ground in a 5,000 pound shoebox with an automatic trans, pinky-effort steering, and effortless access to 24 cup holders. I gave up trying to understand and just hand-wave it away as some kind of American cultural imprinting. In manufacturing, affordable anything means very large volumes to make the math work. Without the volume there will be no product. But that just means stability in the market for the few remaining used cars that are left because there will always be a few of us diehards. We used to call our cars affordable collectibles: X1/9's, 240Z's, Alfa Spyder's, etc. Those cars have begun appreciating and with it comes the financial cover to make needed repairs and restorations. It also means more parts being reproduced etc. I'd much rather have a weekend toy that appreciates 10% a year than a new car that drops in value 20% whether I drive it or not.
 
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I think old Miatas are the affordable collectable sports car at the moment. Maybe 10 years from now the NAs will be the hot collectable ticket but at the moment they are cheaper than spiders and Xs.
 
Cratecruncher said:
How come we are still on these antiquated 12 volt electrical systems?
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Back about 20 years ago (maybe longer?) there was a big push by the auto makers to switch to 24V systems. As computer modules, extensive electrical systems with high demands, sensitive components, stop/start systems, etc were becoming more prevalent, they felt it was necessary to up the voltage and base everything on 24V. Apparently that was already in place in heavy equipment, industrial vehicles, and other aspects of the transportation industry, so they decided it was time to expand it to the passenger car market. It was the big talk of the auto industry trade journals and it seemed unstoppable. I'm not sure what happened but obviously it never happened, and I haven't seen any mention of it for years now.
 
Dr.Jeff said:
Back about 20 years ago (maybe longer?) there was a big push by the auto makers to switch to 24V systems. As computer modules, extensive electrical systems with high demands, sensitive components, stop/start systems, etc were becoming more prevalent, they felt it was necessary to up the voltage and base everything on 24V. Apparently that was already in place in heavy equipment, industrial vehicles, and other aspects of the transportation industry, so they decided it was time to expand it to the passenger car market. It was the big talk of the auto industry trade journals and it seemed unstoppable. I'm not sure what happened but obviously it never happened, and I haven't seen any mention of it for years now.
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I would not be surprised if the rise of hybrid and electric vehicles had something to do with it. The original intent of 24V was to reduce the current carrying requirements by a factor of two. That could result in lower resistive loses and/or the ability to use smaller (i.e. lighter, cheaper) conductors. I believe most of the hybrid and electrics are in the 200V range for the power electronics. We probably won't see 200V power seat or electric window motors any time soon so perhaps there is still a need for more than 12V for those intermediate power applications.
 
dllubin said:
That could result in lower resistive loses and/or the ability to use smaller (i.e. lighter, cheaper) conductors.
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Exactly, Ohm's Law. That was the point about more sensitive sensors and modules that run on very low resistance values. For everything to be accurate and reliable at those levels, the balance of V/I/R needed to be shifted.


dcioccarelli said:
https://www.extremetech.com/extreme/247889-cars-moving-48-volt-electrical-systems
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Actually the engineers wanted to go to even higher voltages than 48, for the reason mentioned above. But the fact that 24V systems had already been established and refined in other aspects of the industry, it was decided this would be a good compromise.
You'll notice the article in the above link is almost a year and a half old, and yet nothing further has been mentioned about this in the trade journals. Furthermore that reference is not a automotive industry publication, and certainly not a reliable source of info inside the industry (no offense to anyone). Just say'n that I doubt it will happen. Especially the 48V aspect; 24V systems could be achievable though. The batteries, alternators, system components, engineering/design, accessories, etc has already be available and proven for decades. In fact in other world markets many electrical components made for the automotive industry are available in either 12 or 24V options. But considering it hasn't moved forward in the last 20 or more years, we might not see it at all. Possibly for the reasons "dllubin" noted.
 
I lived off the grid for ten years through the 80's.
I ran mostly 12 volts because items in that voltage were more readily available.

With 12 volts you can feel a slight nip on sensitive parts of the skin and 24 volts is more noticeable.
If I had a car with 24 volt system I would want the voltage isolated from the car body.
While not considered lethal I imagine 48 volts could give a pretty good bite so for sure would want an isolated system.
With a higher voltage out put I imagine the alternator would take more Hp to turn it thus putting more load on the engine.

Tesla voltage is around 350 volts.

As for charging an electric car it takes less energy than an electric cloths dryer or water heater for example.
Charging an electric car at night is an ideal time because that is when electrical demand usually drops off.
At night power plants become idol and less efficient to operate so there are some electric companies that give lower rates at night to encourage more use.
 
Dr.Jeff said:
felt it was necessary to up the voltage and base everything on 24V. Apparently that was already in place in heavy equipment,
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Yes, been that way for heavy eq. for many years. Two large 12 volt batteries. I wonder if the batteries have anything to do with the lack of increase in system voltage in passenger cars? I know 16 volt batteries are not uncommon in racing applications where the ignition system has high voltage demands. But I'm not familiar with any 24 volt auto batteries. What voltage do electric cars commonly run on?
 
MikeHynes said:
Yes, been that way for heavy eq. for many years. Two large 12 volt batteries. I wonder if the batteries have anything to do with the lack of increase in system voltage in passenger cars? I know 16 volt batteries are not uncommon in racing applications where the ignition system has high voltage demands. But I'm not familiar with any 24 volt auto batteries. What voltage do electric cars commonly run on?
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Tesla, Leaf, Volt and other factory EV's use 350 V or more while most DIY conversions with the exception of a few with deep pockets run 144 V.
 
carl said:
I think old Miatas are the affordable collectable sports car at the moment.
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Unfortunately the production numbers for the Miata means they will never really be collectable with the exception of probably the first year of manufacture and their nod to the English and its mimicry of the 60's Lotus Elan, when they released the BRG version with tan leather interior in the original body shape. They are definitely cheap, due to the large numbers built, 400,000 of the first generation alone, from 1989 - 97. Also, being japanese their improved reliability meant a longer life and less hassles making them a lot more desirable as a daily driver wanting to know they'll arrive at their destination on time.

For me they'll always be a copy of the real classic, the Lotus Elan, much in the same way the MR2 was always a copy of the X1/9.
 
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According to my 1974 shop manual, there is a place on the X1/9 that uses 24 volts. The procedure to remove the windshield calls for putting two 12 volt batteries in series and connecting them to the two terminals under the center of the windshield. Apparently, there is an embedded heating element around the windshield that you activate by putting 24 volts across it and wait until the adhesive gets hot enough to remove the windshield.
 
Actually, early Miata prices have been on the rise for a while now. There are still a lot of them but there are also a lot of admirers.
 
dllubin said:
Apparently, there is an embedded heating element around the windshield that you activate by putting 24 volts across it and wait until the adhesive gets hot enough to remove the windshield.
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That is interesting. Never heard of it. But I think I'd be more inclined to use a heat gun rather than shorting two batteries to produce the heat.
 
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