[Notthatbutton!]

No matter which way I turn I will end up with a $14k battery pack, yowzers! At that rate I could buy 4,000 gallons of gas. Which comes to 128,000 miles at 32 miles to the gallon for small car. I just don't think it's worth it for a daily commuter. Too bad, would have been a fun project. Maybe in a few years battery prices will drop.

[Ziggythewiz]

It really is an investment, of time and money. These batteries should last you 10 years. In that time you'll drive 250,000 miles, and spend $30,000 on gas.

That's assuming gas doesn't go up, but it will. Oh how it will...

[Mr. Fixit]

Heynotthatbutton, Just saw this posting on craigslist if you go with a S10 maybe this setup could do it for you. Spoke to the seller he says these are from a public works department project are used but some are as good as new.
Just thinking outside of the box.

Mr. Fixit for the family
Chris

http://portland.craigslist.org/mlt/pts/2821431273.html
http://www.azuredynamics.com/product...oductSheet.pdf

[electric85]

Originally Posted by dimitri

And that is why you don't see many DIY EVs with 100 mile range.....

You need to reduce your range goal and increase voltage, which requires good controller like Soliton Jr. This will let you use smaller cells, like 100AH or 120AH or 160AH, but more of them, so you can stick them in every nook and cranny of your beetle.

As you are discovering, building EV is all about tradeoffs

it is doable...

http://www.elitepowersolutions.com/e...c_vehicle.html

they used thundersy 200ah that they used to carry, and the thundersky bms they used to carry. i spoke with them and was going to order the same for my fiero...prices were still too high then, and due to time and money i'm still not finished the restoration/conversion

[lowcrawler]

Originally Posted by Notthatbutton!

No matter which way I turn I will end up with a $14k battery pack, yowzers! At that rate I could buy 4,000 gallons of gas. Which comes to 128,000 miles at 32 miles to the gallon for small car. I just don't think it's worth it for a daily commuter. Too bad, would have been a fun project. Maybe in a few years battery prices will drop.

Much of what I've read is that replacing a 30+mpg car with a electric is about the cut-off for it to make purely financial sense when figuring 3.50 per gallon gasoline. ... assuming you did nothing with that extra money other than invest it and use it for gasoline purchases.

That said, as we head for $5 per gallon gas... Things are going to move in the EV's favor.

15k for your batteries might sound like a lot (and it is), factor another 3-5k for the 'other stuff' and then whatever your donor car costs and it's not a cheap initial investment. But if you are looking at the long-term, it does still come out ahead. Especially the longer you drive it.

Also remember that after you've driven your 250k with your pack and it's dropped to 80% of it's original capacity... it's still worth a lot to people and can be sold to recoup much of your original investment.


As for it all fitting in a bug? I don't see a problem with that. I've got a 15.3kwh pack in my bug and it fits completely behind the back seat. I could easily drop 3 of those in the cabin if I didn't mind losing the back seat (which I'm not sure why I wanted to keep it... but I digress). That'd bring me to my max cargo weight of around 1k... and give me a pack that could take me ~150 miles. (with no buffer, of course)

Take a look at Corbins (already linked, but it's worth linking again) http://www.corbinstreehouse.com/blog/plug-bug/ to get an idea of what can be done. His conversion is fantastic.

[Sunking]

Originally Posted by lowcrawler

Also remember that after you've driven your 250k with your pack and it's dropped to 80% of it's original capacity...

That is not even remotely realistic expectation.

[lowcrawler]

Obviously none of us has real-world on this... but...

If, in theory, he puts in a 35-40kwh pack.

Drives 100 miles per day, he's taking it to roughly 70-80% DoD.

Depending on the cells, the manufacturers claim 2-4k cycles at 70% D0D before falling to 80% capacity. (note, not 'dead', just 80% capacity)

Doing the math gets us 200-400k miles. Those 2-4k cycles are measured at .3-.5C, and he'd be pulling 1-2C instead... So we can probably assume it'd be on the lower end of that range. In other words, 250k or so to get to 80% remaining capacity or so... give or take 10% on both numbers.

That's where I get my number from -- just some back-of-the napkin math -- where do you get you "not even remotely realistic" statement from?

[Ziggythewiz]

Originally Posted by lowcrawler

where do you get you "not even remotely realistic" statement from?

Just his general outlook on life and the ideas of others.

[Sunking]

Originally Posted by lowcrawler

Obviously none of us has real-world on this... but...

That is my point. Then winter comes around and all that theory goes out the window.

The EV has the exact same issues it had over 100 years ago, when electric vehicles ruled the road, the battery is the major problem. Th eEV will not become mainstream and widely accepted by the public until consumers are confident they can get 300+ miles between recharges, with all the Bells and Whistles, 10 year battery life, 15 minute recharges, and that cost the same as an ICE vehicle. To do that will require a battery with a specific energy density of 400+ wh/Kg and a charge rate that exceeds C5. To my knowledge there is not even a battery on the drawing board that can do ALL of that.

[Ziggythewiz]

Originally Posted by Sunking

That is my point. Then winter comes around and all that theory goes out the window.

The EV has the exact same issues it had over 100 years ago, when electric vehicles ruled the road, the battery is the major problem. Th eEV will not become mainstream and widely accepted by the public until consumers are confident they can get 300+ miles between recharges, with all the Bells and Whistles, 10 year battery life, 15 minute recharges, and that cost the same as an ICE vehicle. To do that will require a battery with a specific energy density of 400+ wh/Kg and a charge rate that exceeds C5. To my knowledge there is not even a battery on the drawing board that can do ALL of that.

And yet we DIY anyway because we don't care what is mainstream or accepted. In fact, if it were there would probably be far fewer of us here. The world can go on waiting for the tech to keep getting better and better, and we'll build awesome stuff that works now, and upgrade as even better stuff becomes available.