Would double battery = double mileage?

[JasonG]

Originally Posted by Christ

So for a few long trips a year, its better to buy, register, and insure another car?

Build a heavy battery trailer to pull around, including registration and the cost of another battery pack? Power the house? Where do they recharge from?

Buy a parts car from which one could build a pusher with an ICE, including conversion expenses, and registration?

5 kw generator, used for less than $1000, no registration, no trailer, only basic maintenance costs, and alternative use as a HPU when the power goes out...

I know my choice...

I understand what Chevy did, and for them, it was the right choice. Were talking about an EV that already exists, and is driven, and making a simple way to extend the range of it. Cost of mods, as always, is something to consider, even though some don't think so.

Point 1
For $1000, Craigslist has lots of nice cars around here.


Point 2
A 5KW genset running flat out burns 4-5 gal an hour (mine in the sig pic is a 2006 Kohler) that's 10-15MPG @ 60MPH. Heck, the truck pulling the 40 footer can beat that.

[Frank Lee]

Another car? You bet! Especially considering how numerous those trips will probably be. Could have a '91 or older subcompact with collector plates on it (like certain Tempos I know of) only activate the insurance when it's gonna be used, pick it up (or already own it?) for dirt cheap (I won't launch into my success at finding those again).

No, build a light battery trailer Or just go get one from Harbor Freight for cheap.

They can recharge from wind or solar I reckon. Or not mess with it and go ICE.

Yes. Buy a wreck that would make a good ICE trailer. You got it! I wonder if it would qualify for the same sort of permanent registration my HF trailer has? That's a small one-time fee.

Someone should charge up an EV battery bank with a portable generator sometime and let us know how long it takes and how much gas it uses.

[Christ]

Originally Posted by JasonG

Point 1
For $1000, Craigslist has lots of nice cars around here.


Point 2
A 5KW genset running flat out burns 4-5 gal an hour (mine in the sig pic is a 2006 Kohler) that's 10-15MPG @ 60MPH. Heck, the truck pulling the 40 footer can beat that.

4-5 gal/hr? Something doesn't sound right about that?

In any event, here, a trailer is $6/year to register.

Classic and antique plates come with restrictions, usually barring them from long trips or frequent leisure use.

If you don't have insurance, you must turn in your plates. Your driving privilege can be suspended if you don't.

If the trips occur more frequently than a couple times a year, it's probably worth looking into those options. Once or twice a year, I'll just use the generator I already have, and stop for a charge once in awhile.

You could do the math for a pack that goes 250 miles on a charge and figure out how long it would take to charge with a 5kw genset. Nominal output on mine was around 4250w continuous. I never ran it long enough at high output to pay attention to consumption.

[codenamezero]

Oh wow, i had no idea about the ICE pusher concept, thanks for the input.
I've just googled it now, and that's an interesting idea. Interesting, but after analysed the cons, I think ICE pusher is far from cost effective and far from environmental friendly though...

Here is why:

• All the hassles that Christ mentioned above
• The money to purchse used or scrapped car with a running engine, $500?
• Time and money to make the pusher, DIY will be cheaper, paying someone to do it would be expensive
• Ugly, dragging such a weird thing at the back is not visually appealing
• Not aerodynamic, extra wheel drag
• Dead weight, the pusher itself weight more than a 5kW generator
• Pollution, the ICE pusher, I'm sure it won't be a 2010 < 1.5L small displacement engine, and most likely off some scraped 2000 car... and the displacement will most likely 1.8L+

Even if i buy 2x brand new Honda EU2000i, it will only be 200cc (2x98cc), 1.1 gal/ 4 hrs = 0.25 gal/hr x 2 = 0.5 gal / hr max, and it will give me 4kW, and will cost me 2500$.

Building an ICE, will most likely cost you 1500$ minimum.

[Christ]

Hyundai DHY6000SE Silent diesel generator, 5200w, electric start, 230v, 115v

Fuel consumption: .75 - 2 liters/hour, depending on load.

Max continuous output - 4500w

That's what, about 6.5hp? Not quite enough to drive the car at 60mph on it's own, but the 60mph figure for mpg at 2lph:

60 miles using .52gal - 100mpg?

Cost is 1318 British pounds = 2 132.1286 U.S. dollars.

Granted, that's a diesel... Didn't figure they were 10x more efficient than your kohler...

[codenamezero]

Here, this reply from the another Ecomodder thread stated clearly the drawback of the ICE pusher. MetroMPG.com: Electric pusher trailer

After everyone's input, i think adding additional battery into an EV would not be viable... I think having an electric generator would be the way to go...

I also have this concept of a underbody air turbine electric generator... wonder if this concept would work. Basically installing a brunch of small turbine at the end of the car, at the rear diffuser area...



^ At the spot where it begin to curve up, we install 2 rows of small air turbine, so as the car move, it would generate electricity, but i doubt this would generate much power.... lol

Saw an interesting quote from a physic forum:

Originally Posted by http://www.physicsforums.com/showthread.php?t=206100

If you have a forced air velocity of 100 kph = 27.8 meters per sec, and an inlet area of 1.8 meters x 0.6 meters, the air wind power is
Pw = (1/2)ρAv3 = 15,000 watts, where
ρ=air density = 1.29 Kg/m3
A= area = 1.8 x 0.6 = 1.08 m2
v=27.8 m/sec

I would be surprised if you can get more than 5,000 watts out of this if the air is not pressurized (p = 1 bar).

[Christ]

It would likely increase drag, defeating itself by magnitudes.

The charging energy needs to come from somewhere.

[Frank Lee]

The cops never look twice at collector plates. In fact it was a cop that told me to get them after he busted me for expired tabs on my collector car.

Well go ahead and try the generator; personally that would be my last choice. If I was willing to sit around at various points during the trip to wait for a charge, I'd just pack an extension cord and glom onto someone's unguarded outlet for a while.

[euromodder]

Originally Posted by Frank Lee

Remember all the ruckus about Chevy Volt and how their propaganda machine said the genset would only generate electricity, but then the real thing used the ICE to directly power the wheels? Chevy did the right thing.

No, they didn't.
Because they use the ICE to both drive the car itself, and fill the batteries, it's way oversized as a generator.

Audi is going for a small, compact wankel in their electric A1.
I expect it to be somewhere in the 150-250 cc (equivalent) bracket.
15 kW would easily keep that small car going.

[jamesqf]

Originally Posted by Christ

So for a few long trips a year, its better to buy, register, and insure another car?

Suppose it's not a few long trips per year? Suppose you have an EV with (just for instance) an 80 mile electric range, and you regularly make trips of 100 miles. So you drive 4/5 of the way on electricity* and 1/5 on the generator: even if the generator is only half as efficient as using a plain IC-engined car, aren't you still cutting fuel use by 60%?

*Though of course you would not really run the batteries to empty, then run a generator big enough to drive the car, but instead would have a much smaller generator running most of the time.