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Battery Voltage Rising?
|Author||Topic: Battery Voltage Rising?|
posted 12-23-2001 09:19 AM ET (US)
This is a bit OFF-TOPIC, but in the context of a recent discussion about operational problems in newer DFI 2-stroke engines, it was mentioned that some problems were occuring due to marginal battery voltage and high power consumption by the engine at low RPM.
The electrical load in the automobile is increasing, too, and that industry seems headed for higher voltage batteries. I found this article interesting, and should this come to pass in automotive engineering it will probably be quickly adopted in marine outboards, too. See:
posted 12-23-2001 10:26 AM ET (US)
Interesting article, I have often thought this would happen, aircraft use a 24V system as so a lot of commerical diesels ect. 36V would seem to be good for the Auto industry as this is the voltage of most golf carts and electric forklifts ect. But my question is??? Newer electronics are supposed to be more power efficient, and also will this battery really give me more cranking amps when I need it? You can only pack so much current "amps" into a bread box.
Merry Christmas and keep those batteries charged!
posted 12-23-2001 10:50 AM ET (US)
An interesting article, but the writer is clearly not an engineer.
Voltage is not power. Power is a function of voltage and current. A same-size battery that can store the same amount of electrons at 3X voltage does represent 3X watts (power). That allows more power to be stored in less space and with less weight. The power still must be made by the alternator and stored there... It aint free.
A modern, loaded-with-electrical-accessories auto (or boat) has several hundred pounds of conductors, usually copper, to conduct all this current. Changing the power source and device to 36 volts automatically cuts volume, weight and cost of the needed conductors by 66.67%. Digital multiplexing of power switching can cut conductor weight and cost even more.
There is a downside. Insulation. Better insulation and quicker responding fusing (or circuit breakers) will be essential to prevent catastrophic results of a simple short circuit.
I guess I have said enough, except that I predicted this twwenty years ago (well, I predicted 24volt systems).
Red sky at night. . .
posted 12-23-2001 12:59 PM ET (US)
Interesting - but I question the need and the significant impact imposed on the customers. That is, the accessories (radios, cell phones, GPS units, et.al) don't take all that much power - so there isn't justification for a 42 volt system here. By far, the majority of those operating the vehicles do not have a need for 110 volt appliances in the vehicle. Certainly maintenance and construction personnel need remote power sources - but they typically have engine-generator sets. Removing the power-steering pump is a good move (removes a continuously operating pump, belt and saves perhaps 10 hp or so) as many of us have known for years - but you can use a very responsive electrical servo motor operating on 12 volts. Therefore, justification for a 42 volt system is not there. Yes, 24 volt (and higher voltage) systems have been used for at least 50 years that I am aware of - for diesel engines, for aircraft engines and for large commercial engines. But, for the typical automotive engine - 12 volts is sufficient and does a good job. Therefore, justification for a 42 volt system is not there.
The cost of a 42 volt system (new alternator, new battery, new electrical system, et.al) will be significant - very significant. And if they try to implement parallel 12 and 42 volt systems - the costs go up even further. Of course, they could use a 42 volt alternator, battery and starter and tap off 12 volts as needed.
In short, I don't see the justification, the need to support the large price increase that will be imposed. It won't sell. Kinda makes me wonder who is on this MIT consortium - battery manufacturers, alternator manufacturers, starter manufacturers, ... ------ Jerry/Idaho
posted 12-23-2001 09:41 PM ET (US)
Jerry, you missed my point(s) almost entirely.
A .5 KW 42volt alternator is CHEAPER and LIGHTER than a .5KW 14 volt alternator. A 1HP, "36" volt steering servo is CHEAPER and LIGHTER than a 1HP 12 volt servo motor. A 1KW/hr, "36" volt storage battery is. . . .by now, I hope you get the picture.
One third as much money and weight in conductors, motors, alternators.
Those of us who remember 6volt systems and the differences wrought by the 12volt revolution look forward to an even bigger jump in reliability.
Remember, Jerry, we didn't "NEED" computers in cars and boats, either.
Red sky at night. . .
posted 12-24-2001 01:32 AM ET (US)
like we care
posted 12-24-2001 01:44 AM ET (US)
it is funny that we have not changed battery between classic and new yet people who are not buying new could actually care about something so unimportant!
please if you edit, could you please leave original post so we can see your opion not the wreck of words that you may leave behind.
Infrequent poster all the time reader.
And to all who bash everyone else and ME please realize that you are the ones who make this site suck! [Removed ~200 exclamation points--jimh]
posted 12-24-2001 02:39 AM ET (US)
This development in a higher voltage system DOES and Will make a difference in everyone’s life. The impact of this will affect everything from the environment to the weight of power plant accessories, which in turn will increase fuel efficiency. When it carries over to marine applications it will do these things for the four stroke engines.
These things matter not only for me, but also for the future of the generations yet to come. These systems will be able to be retrofitted into today’s and yesterdays electrical systems, which at first it will be expensive later it will be affordable.
By the way this is a wonderful site, the information found here has value, and it is the good people that make up this forum that has made it that way. Everyone here is allowed to express their opinion in a mature respectful manner.
posted 12-24-2001 03:21 AM ET (US)
I failed to mention that one day in the future when we go to repower this will make a difference.
posted 12-24-2001 03:28 AM ET (US)
Appears mjd65 had a bit of "eggnog" today.
posted 12-24-2001 08:52 AM ET (US)
I am not that old (51 !) but I do recall that my older brother's first car was a well-worn 1953 Volkswagen that had a 6-volt electrical system.
posted 12-24-2001 10:18 AM ET (US)
I still have a 1953 Dodge 3/4 panel truck, 6V positive ground!
posted 12-24-2001 11:59 AM ET (US)
I well remember the good old 6 volt days, my first car was a 1937 Dodge convertable that I bought in 1954. Now driving a 1997 F150 I am amazed at the increased technology, can't find the spark plugs in it but the first set lasted 108,000 miles so who cares.
posted 12-24-2001 12:13 PM ET (US)
In highschool I got an incredibly good deal on a 1948 willys pickup. The previous owner had replaced the engine with a big ford V-8 and the electrical system was a jumble of 6 and 12 volts. took a long time to fix the gremlins, but I learned alot and eventually the truck ran most excellently.
posted 12-24-2001 06:20 PM ET (US)
With higher voltages insulation will become a major factor. I seem to remember an article in the distant past which indicated that in excess of 15-16 VDC a spark ceases to be self-extinguishing. In aircraft this problem is covered through very expensive wiring harnesses; can we expect the same for boats which operate in a salt environment with, in many instances, a minimum of preventive maintenance.
posted 12-24-2001 07:00 PM ET (US)
For alot more info go here http://www.sae.org/42volt/
posted 12-24-2001 07:37 PM ET (US)
JB - I understand your points quite well - and yes - increasing the voltage allows the weight of some components to be decreased. However, realize that the weight of some will also increase - for example, pick up a 12vdc battery from your car or pickup and then pick up a 24vdc battery from a Kennworth truck. You will find that the 24vdc battery is about twice as heavy. Or pick up a 6vdc battery and then a 12vdc battery. But realize further, the capacity of a battery has a larger effect on weight than does the voltage.
I would expect the weight difference between a 12vdc and a 42vdc system to be a few (10 - 15) pounds exclusive of the batteries - as opposed to the "...hundreds of pounds..." mentioned above.
But regardless, a few pounds difference in the weight of the electrical system is insignificant when compared with the total weight of the vehicle (car, SUV, boat or et.al) and then will not have a measurable effect on the operation or performance of that vehicle.
Some have referred to the change from 6vdc to 12 vdc. That change was made for good reasons. Recall that when we used 6vdc batteries, the engines were of lower power, smaller displacement - and then people wanted more power, bigger cars, faster cars and this cycle escalated upward. The result - bigger engines - which, by definition says larger engine starting power requirements. And with the higher power requirements came the need to go to a 12vdc electrical system.
Today however, the automotive market is going the other way - smaller cars, smaller engines - and therefore, decreased engine starting power requirments. So, there is not a need for higher power starting systems.
Another issue not brought up before - but if you go across 12vdc, you will receive a mild shock. If you go across 42vdc, you will receive something that may be akin to a kick by a mule - at best. Seriously, direct current is much more dangerous than alternating current. This aspect is frightening - the sue happy legal system that exists today will dance with glee. But to me, safety is a necessary requisite of any viable engineered system. Incorporating the necessary safety related systems/devices would be yet, another expense.
JB states that the 42vdc components will be cheaper - though I don't have expertise in the design or manufacture of electrical components - I would seriously doubt that this would be the case.
And therefore - I still feel that the need and the benefit are not there to justify the big cost increase that will be imposed on the buying customers. It will not sell. -------Jerry/Idaho
posted 12-25-2001 08:51 AM ET (US)
Folks no sense in debating the issue, it is a done deal --- Here for your reading pleasure from our Canadian friends is a brief article giving you the reasoning and general considerations for moving forward to a 36/42 volt system --- enjoy --- http://www.canadiandriver.com/articles/jk/at_010515.htm
It is the season to be Jolly --- ho ho ho
posted 12-25-2001 10:27 AM ET (US)
That Kenworth battery has more kilowatt hours
than the 12v battery, which is why it is
heavier. Lead acid batteries of the same
kilowatt hours will weight about the same.
Compare West Marine SeaVolt deep cycle
AH Pounds KW-H KW-H/Pound
posted 12-26-2001 06:59 PM ET (US)
As for the confusion about the computer circuits running 5v, talk to the computer makers. Your Oxygen sensor runs about 0.5vDC and has been for the last 20 years. If you want more voltage on the circuit, drop a signal amplifier near the signal and push 25vDC to the computer if it will work better for you. Otherwise, make a more water resistant connector with gold plated conductors, and run low voltage.
Having just finished shopping for a newer vehicle, I can honestly say that there's too much fluff on the average vehicle out there these days. HID lights draw less current than a pair of 9004 bulbs, but cost $300 each. If Electroluninescent stuff draws so much current, how does Timex make an indiglo watch run off a watch battery for 2 years? LED tail/brake lights draw 1/10th the current of a 1157 bulb, but cost 100x as much. How much is TOO much to be asked to pay for a new vehicle?
As for removing my continuously operating power steering pump and replacing it with an electric motor, remember: Converting mechanical energy to electrical energy and back to mechanical energy is inherently IN-efficient. If it were efficient, we would have had an electric power steering rack 35 years ago.
My vote for doing something useful with a wasted byproduct of an internal combustion engine is to find a way to harness the thermal energy we give away through the radiator. Remember when you could pull a loaded train with a coal fire and a tank of water? How about a steam assisted power steering?
I loved the comment about mounting the battery in a "hard to get area" to avoid service by the casual consumer/hobbiest. When was the last time you saw a new car with an easy to get to battery? So much for jump starting anything, can't use the whaler battery if the car is 42v... I think I'll pump up the tires on my mountain bike with a hand pump and pedal to work. Remember, these new concepts are from the same guys who only offer a 3yr/36k mile bumper-to-bumper warranty on their new cars. (Delphi was part of GM not too long ago). Wait until they build the car around the battery so the car becomes disposable like a disposable flash light... it's coming...
posted 12-26-2001 07:15 PM ET (US)
Hi, Jerry. I am not inclined to write a textbook on the subject, so I am prepared to agree to disagree. Peace?
Red sky at night. . .
posted 12-26-2001 11:59 PM ET (US)
The last thing we need is a text book by JBC on this forum.....LOL
posted 12-27-2001 10:15 AM ET (US)
One advantage of LED brake lights is shorter
ON time. Watch the CHMSL (Center High-Mounted
Stop Light, correct term for the third brake
light) on cars ahead of you. You can see
that the LEDs come on more quickly than the
other two incandescents.
Don't compare incandescent bulb prices to
The battery in my Nissan Pathfinder is right
The P-51 Mustang had a radiator assembly
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