Thursday, December 21, 2006

Got a few batteries to try and test

I got some 10,000mAh NiMH D-sized batteries, and some 16850 PCB protected li-ion cells to test/fiddle around with. Need to figure out a way to charge/keep these in balance if I ever do figure out how to use these in a EV car sized pack, though.

Wednesday, December 20, 2006

A lot of EV's in traffic congested London

I've read somewhere that there's 750+ EV's in London, most made by a company from India, and it's getting more and more popular. It's very crowded in London, and these cars are exempt from a 8 pound per day congestion tax, which probably accounts for their popularity. The city of London is trying to reduce the number of people driving big 4x4's, and the car tax exemption sure seems to be working.

Check out the below video, the car is really small! I'm sure it's been street safety certified but I still wouldn't want to be in an accident in that.

Monday, December 11, 2006

Decided and purchasing battery for EV!

So, updated battery spreadsheet again. Changed the assumed Wh needed per mile, costs, etc, to better hopefully reflect reality, and to make the numbers more on the conservative side. Settled on UB12350 batteries, 29 of them for a 348V system, of 696 pounds weight, with a energy storage capacity of 8526kW. Assuming 250Wh per mile, this gives a 34 mile range, which is ok for now, at least until lithium technology becomes cheaper. Hopefully that will be soon! Lots of interesting technologies out there, from Firefly and AltairNano, etc.

Monday, December 4, 2006

I love my keyboard

Was looking at my keyboard, and thinking how I bought it freshman year in college. Been using it ever since! The date of manufacter on the back says 09SEP86. :) 101-key IBM "click-ity" keyboard.

Thursday, November 30, 2006

Batteries, Batteries, and more Batteries

Did some more research into batteries, and updated the spreadsheet linked in the previous post. looked at tons of sites and tons of batteries, and decided on this one:

UB12500, with a total pack voltage of 348V, weight of 957 pounds, at a cost of under $2k total hopefully! The range I calculated was 61. I'd like a range of 80+ at least though.

Thought about paralleling NiMH batteries, found a place that had AA NiMH 2600mAh for 75 cents each! This is comparable to lead acid prices. Unfortunately you can't parallel NiMH batteries at least not without a complicated BMS. Is there an easy way to parallel NiMH batteries?

Saturday, November 25, 2006

Battery choices, narrowed it down

So, been researching batteries lately, and though I'd love Lithium, it's just way too expensive! So I'm settling for a Deka Intimidator D34. It'll weigh 1063 pounds, but I think I can get that to work, if not, I can always remove 2 or 3 cells.

I used the above spreadsheet to calculate and estimate range/cost/weight, etc. Click the image to view a bigger version. Original spreadsheet here.

Thursday, November 23, 2006

Something I read posted online

"We had the better batteries 10 years ago. The Ovonic NiMH. 70 wh/kg specific capacity, 1,750 cycles to 100% depth of discharge. Robert Stemple, chairman of Energy Conversion Devices, quoted them at $150/kWh for a production run of 20,000 cars.
General Motors, not wishing to see the electric car go mainstream, sold the patent to Chevron Texaco. Chevron Texaco vigourously protects this battery and has sued Toyota for making a similar design. Further, with the oil company winning that case, it can now restrict the maximum AH size of the batteries to 10 AH. This prevents them from ever being used in a road EV, as it is not practical to go above 400V or so and NiMH cannot be charged in parallel with ease. Further, this oil company is responsible for about half of the price premiums on Today's hybrids; they charge $1,200/kWh for the battery when it could be much cheaper!
At 70 wh/kg, a midsize car with attention to aerodynamics could have 200+ miles highway range with a 500 kg, 36 kWh pack costing $5,600 and lasting well in excess of 300,000 miles in theory. This battery has been denied to us. This battery would allow hobbyists to make 120-150 mile range conversions a norm, and 200-300 mile range conversions a possibility."

Not sure how accurate the numbers are, but the fact is that we can't get a technology that works because of this. Companies are allowed to protect their revenue stream, but this sure makes Chevron and GM look bad.

Wednesday, November 22, 2006

Waiting for Motor, Inverter to arrive!

I've ordered a MES-DEA system, 30kW continuous, 90kW max power (about 100hp+ or so).

Waiting for it to arrive, wish it wouldn't take so long. :) I feel like a kid waiting for a toy to arrive. Trying to come up with the battery system now in the meantime.

Been reading up on EV conversions, and the pro's and con's (look at FAQ #6) of auto versus manual transmission, and I've decided to stick with a manual, but without a clutch. Supposedly you don't need a clutch? I'm still not quit sure how it all works, though, so I'm going to keep the clutch and clutch pedal and just not use it. Going to remove the flywheel for reducing rotational mass, which I think is ok.

Added the car to evalbum.

Thursday, November 16, 2006

Purpose of blog

Purpose of this blog is to document a project I'm doing for fun. We are converting a Scion Xa into a fully electric vehicle. It will have a AC motor, either SLA or NiMH or Lithium batteries, and hopefully a range of 120+ miles.