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Discussion Starter #1
Next week I am planning to buy batteries to build my pack. I have eliminated a few and have a few to choose from, looking for new batteries any type cell or pouch that carry atleast 8AH and up with a high C-rating? Here are some:

Headway - My number 1 choice because they are easy to build, and carry a good C-rating. The only problem I see with Headway is they are 300grams each and large.

A123 & K2 - Great batteries but I donot want to weld 500 batteries together.

LifeBatt - C-rating not high enough for drag racing.

Dow Kokam - salesman likes to play games and never answer all the questions on availability and pricing.

FullRiver - salesman never returned email with pricing, gave me product number, but no pricing and availability.

Anyone have any other batteries? :confused:
 

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15000 rechargable NIMH size AA here at 1.8ah. I take them all out every night and plug them in 4 at a time on my desktop charger. :) Nah just kidding! Actually I do use a few of those things for stuff like my wireless keyboard but they don't last many cycles before they give an error light on the charger. I bet I can't get 10 charges on some before they fail!

I'm using 1500lbs of lead to take me a whole 30 miles before walking! But only cost $2300. That was when lithium was running about 12000 for a decent size pack. Now I'm in the middle of crunching numbers to see if I can justify spending about $7000 on a much smaller KW pack. I want to build two parallel strings of smaller batteries.

I'm considering Calb and Hi Power. Those two stick out to me as ones that people have had good luck with and they have pretty good specs ie low internal resistance versus TS.

Seriously am considering building a pack of about 2400 or more Panasonic 3.7V, 2.9ah cells like the Tesla roadster uses. Lots of research to do for this option and have yet to have found a price below $7.25 ea. Supposedly you can build a pack for 25% of the cost of prismatic batteries and they last longer due to being enclosed in a steel cylinder, have built in protections prismatics don't have thus they are safer. The Tesla uses 6800 of them to drive 200+ miles.
 

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Headways are probably a good place to start, but for real racing it would probably be just a step, and you'd want to upgrade once you find their limits. It would get you in the game, get your car on the track, make a name for yourself and once you've done all that perhaps Dow Kokam and the rest would return your phone call. White Zombie was pretty fast on lead, I'm sure using headways you could be much faster if you put it together right.
 

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Discussion Starter #5
Thanks, I think we will get good times with the Headways. Let's see what the car does with one season running Headways then maybe next season I will upgrade to some pouch packs. ;)

Headways are probably a good place to start, but for real racing it would probably be just a step, and you'd want to upgrade once you find their limits. It would get you in the game, get your car on the track, make a name for yourself and once you've done all that perhaps Dow Kokam and the rest would return your phone call. White Zombie was pretty fast on lead, I'm sure using headways you could be much faster if you put it together right.
 

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Discussion Starter #6


The battery pack that will make Tesla’s upcoming Model S luxury sedan run.
(Credit: San Jose Mercury News. Courtesy of Tesla.)
Tesla Motors is most known for its all-electric sportscar, the Roadster. The Model S sedan will be released soon, and the battery pack used to power this model was unveiled.
The San Jose Mercury News reports that while the battery pack for Tesla’s Roadster is essentially a large box containing thousands of individual battery cells, the Model S battery pack is flatter and nearly the width and length of the car. It lies beneath the floor of the car’s cabin and can be swapped out as needed.
“The Model S battery is perfectly flat,” says Peter Rawlinson, vice president and chief engineer for vehicle engineering. “We’re using the battery pack as a structural element of the car.”
Tesla plans to manufacture 20,000 Model S sedans, using the design of the battery pack as an aerodynamic element of the car. This jump in manufacturing is expected to offer about 500 new jobs.
For the Roadster, Tesla strung together nearly 7,000 laptop batteries into one battery pack. But for the Model S, Panasonic and other Li-ion vendors are creating batteries specifically for an electric vehicle. Tesla has yet to choose a battery vendor for the Model S.
Practically every company that makes a Li-ion battery has sent its cells to Tesla, which puts them through rigorous testing, with a focus on extending their life and safety. Tesla has not chosen (or perhaps revealed) its Li-ion manufacturer yet.
Tesla claims the energy density of the Model S battery pack will exceed 135 watt-hours per kilogram. The sedan, which will be capable of going from 0 to 60 mph in 5.6 seconds, will come with a choice of three battery packs, capable of ranges of 160, 230 or 300 miles.
The base price for the entry-level Model S with a 160-mile range will be $49,000 (after a $7,500 federal tax credit).
 

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Discussion Starter #7
You have to love Elon Musk, he has a set of brass ones!

Remarks come in the wake of Nissan bragging that it is far ahead of competitors


If there's one main factor that is turning people off from truly considering electric vehicles for their next purchase, it is the price. Thus when Nissan claimed to have reached production costs of $375/kWh for its upcoming 2011 Nissan LEAF EV, it turned heads. After all, most auto companies were saying that they hoped to reach $400-$700/kWh with their upcoming models.

Tesla Motors CEO Elon Musk is not impressed with Nissan's claims, though. While he does not comment much on the battery cells themselves, during a call to analysts and investors he blasts Nissan's supporting systems, saying that they are more primitive than his company's first prototype.

At issue is the fact that the LEAF uses air cooling for its batteries, while Tesla uses a superior liquid heating/cooling thermal management solution. By opting for the cheaper air cooling, Musk says Nissan's battery temperatures will be "all over the place". Worse yet, he says that they will undergo "huge degradation" at colder temperatures, and literally "shut off" at warmer ones. Competitor GM has stated that its 2011 Chevy Volt EV may have similar issues.

Tesla Motors' current system for the Roadster sports over 6,831 laptop-sized battery cells designed for automotive use. It packages cells together in modules and then places modules into a full pack. Each module is equipped with liquid cooling and temperature sensors. Firmware controls the rate at which the cooling fluid (or heating in cold weather) is pumped through the system, responding to changes in heat.

Despite having a huge profit margin on its current Roadster, Musk says that his company is "giving up" hopes of overall profitability in exchange for "pretty astronomical growth." Tesla is instead opting to spend up to $500M USD (currently its hoping to stick to under $400M USD) to develop its new Model S electric vehicle.

Musk says the new vehicle will sport significant improvements to its battery. It will feature 50 percent more density per module -- meaning that it will pack 3 cells into a similar sized module for ever 2 of the Roadster's pack. It also ditches the expensive all-cobalt electrode in favor of a nickel cobalt aluminum cathode (positive electrode). The new composite cathode will be much cheaper, while not significantly impacting performance.

The company has not revealed the cost per kWh that it's targeting for the Model S. In 2009 the industry average, according to a Deutsche Bank report [PDF], was $650/kWh, but current orders being placed for the 2011/2012 timeframe are averaging $450/kWh. The rapidly dropping prices are helping to cut the cost of laptop batteries as well, which are priced at $350/kWh, according toLG Chem subsidiary Compact Power’s CEO Prabahkar Pati. Pati says that low price is a sign of things to come for the auto industry.

Tesla Motors plans on having an "Alpha" version of the Model S built later this year. That version will be 80 to 90 percent complete in terms of production intent. Then next year it will build a "Beta" version, which will be 99 percent complete. The production Model S is launching in 2012 priced at $57,400 USD.

While that price may seem high, price inflation may make it more competitive. Some dealers of the upcoming Volt EV are reportedly adding $10,000 to $20,000 USD markups on to its base price, raising the cost to as high as $61,000 USD before tax credit.

Still pressure is on for Tesla, which lost $38.5M USD in its last fiscal quarter, bringing its total losses for the year to $68M USD -- over $10M USD more than it lost all of last year. The company has an upcoming contract with Toyota to produce an electrified RAV4 that also promises great future payoffs, but at the present is sapping cash.
 
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