Re: Hybrid Lovers Read This and Lament

OK I was not entirely correct. They would NOT need to design a trailer for the LA batteries, they will need to design one for the LA batteries AND an engine driven generator. Ask Mr. Ohms this question. Why are the 12v battery and the starter in my V8 Lincoln so much larger then the ones in a motorcycle, neither one of which needs to motivates the vehicle in question? Why don't they just use 8 AAA batteries and a starter the size of a windshield wiper motor? ;)

mike

I think Mr. Ohms did not give you a complete reply when you asked him.

Different battery technologies have different voltages per CELL. A normal flashlight battery is a single cell that produces 1.5v. NiCd battery cells produce a little under 1.5v. Lead acid battery cells produce 2v per cell

-- a normal 12v battery has 6 cells in series.

There are 2 other factors that are key to battery usage:

1. Internal resistance. This really determines how large a current the battery can deliver.
2. Capacity: how long can the battery deliver the necessary current?

Now, to replace a battery with one of a different type, one would have to match the voltage and the internal resistance (otherwise it would not produce the necessary power) of the original. To build a small 48v LA battery is not hard -- it just requires 24 cells, each of which could be quite small. The overall size need not be bigger than a standard 12v battery.

The next question becomes the capacity -- or really, the energy storage density. How much energy can you store in a given weight or size?

Finally, as was mentioned earlier, charging would likely be a problem when replacing one type of battery with another: a charging profile that works well for one battery technology may kill another quite quickly.

So, it's not just about what Mr. Ohm says, but also what Mr. Capacity says and Mr. charging profile.

So, the question should be: Will they also design a trailer to carry all the LA batteries need to store enough energy?

Whoever wrote: >

Exactly. I didn't realize they used a nominal 48V. So to modify what I said in my previous, you could get the 48 volts still with a pocketful (6) of 9-volt transistor radio batteries. Like you said - you have to have the energy/power. That's why I said that voltage is only half the equation.

Since we're being picky, as with all units named after a person, the convention is to capitalize the 'V' when *abbreviating* "volts", and to

*not* capitalize it when writing it out. For example, you would write "48 volt battery", or "48V battery". :)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

I am not claiming that they use 48V. This may be correct, or not. I have read that there are some plans to move all vehicle systems to 48V.

Thanks for the correction. I should have remembered that. I have even been to Volta's birthplace.

We can only hope that you return to Volta's birthplace soon and spare us further painfully boring rhetoric. You two could drive old people to fornicate!

:-)

Very funny, I'll admit I laughed.

But seriously, in a hybrid, the battery is simply used to store braking energy, it is not used as power source like batteries are in an electric car. The energy comes from the gasoline engine, the battery capacity only needs to be big enough to store a reserve.

has already demonstrated a working electricvehicle retrofit on the Prius that REPLACES the existing Prius NiMH battery and Toyota battery control computer. They aren't selling it yet - for obvious reasons - no demand since all the Priuses are still under battery warranty. But their install keeps the gasoline engine, which means that for a Prius to be a candidate for this company, it really needs to have a shot battery that isn't under warranty, and a gasoline engine that is expected to last at least for the following decade, in order to cover the expected life of the replacement system

I think this is not a particularly valid approach - because Toyota's battery warranty is going to insure that by the time the battery comes off warranty, that the gasoline engine in the Prius will be shot.

A better approach I think is to gut the battery and engine and computer and all that garbage out of the vehicle, and install an even larger battery pack and charger and make it fully an electric vehicle. It would, of course, kill it's usefulness for long distance interstate drives of hundreds of miles, but it would be still very useful as an around-the-town vehicle.

The General Motors EV-1 program demonstrated that there IS a market for fully electric vehicles. Lots of people screamed when GM took back their EV1s. The problem with the GM initative is that the demand wasn't large enough for GM to make the EV1 profitably.

BUT, in a decade or so when there's lots of used Priuses that have shot batteries, not under warranty, and shot gasoline engines, why then the economics will be quite different.

There have been people doing electric cars for years - Flight Systems Inc. for example sold plans to convert a Chevy Chevette to full electric, using a 6 volt lead acid battery bank, back in 1982, that would go 30-40 miles on a single charge. A book "build your own electric vehicle" by Bob Bryant in 1994 did a 1993 Ford Ranger pickup conversion that would go 75Mph and got 60 miles to the charge that also used lead-acid batteries.

The only difference between these two more low-tech approaches and the higher-tech edrivesystems approach, is the edrivesystems approach uses lithion ion batteries, and a computer to manage power and charging, while the older designs used simpler electronics and lead-acid batteries. The higher-tech approach is more expensive and gets you a greater range, but the lower-tech approach could be done by anyone in their garage.

So yes, I do think that when the warranty ends on the traction battery in a hybrid, that there will be lots of choices other than to drop $5000 into a new traction battery, into a vehicle that probably has about 4 years of life left in it's gasoline engine.

Ted

It is used as a power source, just not the only power source. There are many modes of operation where the power required by a hybrid exceeds what the gasoline engine alone can provide and then the battery pack is a power source.

They proved that there was a market for HIGHLY subsidized electric vehicles. If they had charged what these vehicles actually cost them, they market would have likely been zero. A subsidized market doesn't reflect the true underlying demand.

Yep, the glow will wear off in a few more years as the first vehicles begin to require substantial maintenance and replacement of expensive components.

Matt

Or, better still:

48 V, which is the actual official way...

DAS

For direct contact replace nospam with schmetterling

Try driving one below a certain speed for more than 20 minutes and see what happens.

This is a vehicle that takes gasoline as a power source, there is no plug for a charger. I understood it only stores power generated from braking but if they are powering it from the battery for low speed operation, they are obviously running the gasoline motor in a way as to produce more energy to motivate the car, and sucking some of that off to charge the battery. Nevertheless, the battery does not produce power out of thin air. It either comes from regenerative braking or from the gasoline engine. Thus the battery capacity does not need to be as large as a fully electric car. I still think it would be quite easy to substitute lead-acid batteries for the NiMh traction battery, assuming you wanted to preserve the gas engine and such.

The significant thing here is that in the Prius or other hybrid you have a complete vehicle chassis with an interior, carpet, seats, etc. and powertrain that is fully electric. 80% of the work is done for you in building an electric car, all you have to do is gut the gas engine and traction battery and the Toyota computer, and put your own batteries in, configured to supply the power that the Toyota traction motor requires, and add a charger.

Clearly in old used Priuses, the traction battery and gasoline engine will wear out long before the electric traction motors do. It is really a ripe candidate for a conversion once that happens, since you will be able to get them for practically nothing, and nobody is forcing you to replace their guts with Toyota's rather expensive hybrid system.

Ted

If AAA carbon batteries could supply the high current needed they would do it, but if that was the case AAA batteries would be somewhat dangerous to use in consumer applications.

You can take 8 AAA nicads, fully charged, and draw an arc with them, though. (OK, a small one)

Ted

A group of researchers built an interesting mod to a Prius (or some other hybrid). They added more batteries - but not enough for a long range -- and a charger.

The result was a vehicle that could cope with a short commute using energy from the overnight charge, while long distances could also be achieved through the gas engine. The overall fuel economy (and vehicle cost) was significantly greater than that of the original hybrid, while the range was grater than that of a 100% battery vehicle.

Yes! And a recoil starter, just like on my snowblower for when the batteries get weak! :) :)

Ken

Hi...

If one is foolish enough to put 4 AA nimh's in their pocket while bike riding with their grand daughter, they can burn their leg terribly painfully, leaving a bad scar :(

Don't ask me how I know that, eh? :)

Yes, that was the

link that I already posted. Ted

One thing is true about any new technology the owners are like the early pioneers, and you know how you could tell who the poineers were? They were the ones face down with arrows in there back.

To paraphrase Mae West: "Is that a pair of C-cells in your pocket or are you just happy to see me?"

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Would the pull cord be long enough to start the motor from inside the car? LOL

mike

Heh heh! I don't know if the big diesel manufacturers still do this, but when I was a kid, I remember being told (probably by my dad) that the Caterpillar scraper engines used small gasoline engines (with their own electric starter of course) to start the main engine. Not sure if the starter engines were one lungers or something bigger. I think also, in some large engines, electric motors spin up a flywheel to start a larger main engine (some WWII aircraft engines sound as if they use such a system).

Theoretically you could probably transfer the total energy of a few C- or D- cells into such a flywheel system (or a large capacitor for that matter) over a minute or two - use them once, then throw them away. Not sure if a handful of AA's have the total energy necessary. "Give me a big enough lever and i can move the earth." :)

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Google for "Coffman Cartridge"