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etmax
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Re: Why not just be rid of the 12v battery altogether?
etmax   8/14/2013 10:33:26 AM
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Not having to start the car any more the 12V battery would only need to have a 1/4 of the capacity.

etmax
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Re: 48 Volts
etmax   8/14/2013 10:26:15 AM
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But lithium batteries are safe, they are certified for use on aircraft! Oh wait, I think several planes were sent to the shop due to in flight fires :-)

etmax
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Re: Miraculous EU Marketplace
etmax   8/14/2013 10:22:42 AM
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:-) I agree, and it's not always the best ideas that make it, only the ones that capture the imagination of the buyer/are better marketed (to a point). As a funny life experience with start/stop technology, in 1972 I had the clutch cable break on my 1965 beetle while waiting to drive on a ferry. I turned off the ignition, put it in reverse and turned the key then did the same in forward/reverse/forward again doing a 3 point turn and then proceeded to drive to a workshop by the same means. Once in first I could change gears by revving just the right amount AND THAT WAS A 6 VOLT SYSTEM :-)

but i do agree, even though every actual start/stop car I've driven this year has been a 12V system, charge recovery has to be better with higher voltages.

Someone will have to figure out at what fuel price point the expense of 48V etc. is justified.

If I may ramble on, I have often wondered about start/stop from an emissions and consumption standpoint, because a partially warmed engine uses about 20-30% more fuel, has significantly higher engine wear, and emissions are more difficult to control during warm up as well. This is partially because of catalytic converter temperatures. I know they can electrically heat them, but that's more fuel too, so I would be interested in knowing how much benefit there is if you're not stuck at a level train crossing for 10 minutes. I'm not saying stop/start isn't a good idea, only asking is it? and how good?

Charles Murray
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Blogger
Re: Miraculous EU Marketplace
Charles Murray   8/13/2013 6:37:30 PM
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As you point out, there are a lot of very good reasons to question the viability of this idea, etmax. The one big thing it has going for it, though, is the inevitability of start-stop technology. Higher voltages are better for the operation of the starter-generator. And 48V lithium-ion is better at capturing that regen energy. As you say, it will be interesting to see (and if) this pans out.

Reliabilityguru
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Gold
Re: Miraculous EU Marketplace
Reliabilityguru   8/9/2013 9:30:22 AM
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EU prices range from $7/gal in Spain to $9/gal Norway. Almost all are between 8 and 9. The difference in price between US and Europe is taxes.

More of what they pay goes to big government than big oil. One would think big government was not just overhead.

etmax
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Re: Miraculous EU Marketplace
etmax   8/8/2013 10:35:14 PM
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Hi Charles, I often wondered why a technology (42V) that even Delco was touting as being the next big thing died, but at the end of the day it did add a lot of unnecessary cost at the time. Now 48V and a lithium battery it seems an even greater cost is being introduced, and given the deadly combination of a lithium battery and lots of falmmable plastics and fuel I thing the battery will have to be armour plated and placed within the confines of the passenger safety cell to avoid a catastrophe in an accident. Another show stopper I see is the LV directive that cuts out at 42V (possibly one of the reasons why 42V was chosen) so it will be interesting to see how it pans out. I don't think I'm going to hold my breath, as to me it looks like another attempt to sell a new idea for not too much added value. I've don't measurements on my car and the A/C uses very little, something around 1-2%

MVRS
User Rank
Iron
Re: 48 Volts
MVRS   8/8/2013 10:33:27 PM
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Put the battery in the trunk (like some cars already do).  The climate is more temperate than the engine bay.

etmax
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Gold
Re: 48 Volts
etmax   8/8/2013 10:14:36 PM
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You have hit the nail on the head, 42V is the upper limit of the LV directive which covers most of the globe. An auto electrician wouldn't be able to work on a 48V system in most countries

 

etmax
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Gold
Re: Miraculous EU Marketplace
etmax   8/8/2013 10:09:26 PM
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I don't think you can blame unemployment on current fuel prices, the US has very low fuel prices (based on global levels) yet has much higher unemployment. If anything that would indicate that high fuel prices lower unemployment. Of course that isn't the case either. What it is are 2 things, first there are not enough people earning enough money to be able to spend it in the wider economy therefore the economy is sluggish. If some of the money that is in the hands of the super rich and is spent on enormous mansions and $1000 handbags were distributed to the 30% of the population that can only afford to eat and shelter things would look better

AnandY
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Gold
RE: 48 V my answer is a YES
AnandY   8/8/2013 3:26:15 AM
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 The lithium ion battery technique will enable for the recapture of battery energy as it has been put by Charles. The use 48 V in the locomotives will no doubt lead to a cheaper and efficient method of locomotion. The answer to 48 V is therefore definitely a yes.

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