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Electric car battieries Answered

Hello, I need some help. With gas prices getting to an excess of $3.50 in Texas, I have decided to make the switch to electric cars. I was watching a show on TLC the other day about a guy in California who converts cars to electric. He converted an old heavy-as-can-be Camaro into an electric car that could peel out. I found a website that sells conversion kits for all kinds of cars called Cloud EV. I want to buy the heavy car kit, but the only snag I hit was this: I need 60 batteries to get a day's power, but it will cost about $3000 to $5100 (1949.6978 Euros to 3314.48625 Euros)!!! Can anyone help me find a cheaper source of batteries? Car batteries are just to expensive. Thanks.

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CameronSS (author)2008-05-07

Battery prices have gone up recently as the price of raw metal has skyrocketed. There's a lot of lead in batteries. If you want a cheap source of batteries, deep-cycle golf cart batteries from a place like Deka or Trojan are your best bet. Ni-MH and Li-Ion will actually give you more range per pound for your dollar, but cost much more.

Also, where do you get this figure of 60 batteries? 60 12V batteries is 720V, far more than you would ever use in an electric. Their "large car" kit is rated for 132V-144V. Using 12V batteries that requires 11 or 12 batteries, with 6V batteries it requires 22-24. The truck I drive uses 20 6V cells-a 120V system.

I would highly recommend doing much more research than watching a TV show. I also notice that you do not mention what car you are going to convert. Buying components before you know what you are putting them in is kind of foolish. If your goal is simply to save money, building an electric isn't really going to save you much. They are still expensive-not so much to drive, but to build.

I will direct my dad to this forum; perhaps he can answer your questions better.

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user

I have done a lot of research. The reason I came up with 60 batteries is this: It takes 12 to get the 144 volts. You make 5 packages of 12 12volt batteries. Then you hook up those packages in parallel to create more amperage thus giving you much more power/range. here is a schematic.

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60 batteries at about 75 pounds apiece is 4500 pounds. You will have an unbelievably heavy pack, and you will crush the suspension of anything less than a Hummer. A typical EV conversion already requires you to at least add an extra leaf spring, and that's with only a 1000-2000lb battery pack. In addition, the added weight means that you will lose that acceleration that you seem to be after.

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Patrik (author)CameronSS2008-05-08

Based on the prices and the website he posted, I assume he's looking at 60 20Ah, 13.76 lb batteries, or 24 45Ah, 31.04 lb batteries.

The first option would givie him 100Ah at 144V, for 825 lb, $5100. The second would be 90Ah at 144V, 745 lb, $3120.

Still heavy, but far more reasonable than your 75 lb batteries...

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CameronSS (author)Patrik2008-05-08

That poses a different problem. Even though more small batteries will give the same kWh performance as fewer large batteries, you will have five times as many connections. Each battery requires a giant 1/0 AWG cable to connect it to the next, and every cable requires two giant crimp terminals. Both are comparatively expensive, and both will generate heat, and therefore line losses. Also, when cycling batteries as often as you do with an electric, you must monitor the level of water in the batteries. As batteries are charged and discharged, sulfuric acid is converted to water and sulfur, then back again. In the process, some of the water evaporates, and it must be replenished monthly with distilled water. This is somewhat time consuming, and having 60 batteries to check and fill will take 5 times as long as 12 batteries. This is not an issue if you are using Ni-MH, Ni-Cd, SLA, AGM, or Li-ion batteries, but it is vital if you are using normal, inexpensive "floodies."

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Big Bwana (author)CameronSS2008-07-01

If your going to use such large packs why not go with forklift batteries or 2 volt cells so if one fails your only pulling one out and changing it... And forklift batteries seem to last a good few years if they are not abused to badly....

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Patrik (author)CameronSS2008-05-08

True that! I should just shut up now - I'm just trying to reverse engineer the setup that I think gimmelotsarobots might have in mind. Far better to let him duke it out with you guys himself... :-D

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user

I've seen it done, but like I said before I will most likely not use that many. Thanks for the weight estimate though. :0

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user

I don't research through the TV. I have found many other sources like cloud ev, evalbum, and ausitn ev. I know the build will be a pocket drain, but in the long run it will be cheaper. I am also trying to find a good car, but these kits are universal. There is one for every car size.

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user

I apologize, then. The only source you mentioned was the TV show, so I assumed that you, like so many others, had simply seen a video and decided you want to convert. I'm glad to see that you have checked out some good websites...Then again, I know the guy who created and maintains the EV Album, so I have to say that, just in case Mike's watching me. I highly recommend seeing if there is an EAA chapter in your area-There you should find people who have already gone through the process, and learn from them.

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Patrik (author)CameronSS2008-05-07

I assume he's not planning to put all 60 batteries in series, but rather that's how much total capacity he needs. E.g. 5 parallel circuits of 12 12V batteries...

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user

I really don't need 60 batteries, but imagine how far I could go! In reality, I only need 24 for a good 30-40 mile range.

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westfw (author)2008-05-08
There was a Good Article recently in Design News Magazine. Depressing, though:
  • Gasoline packs 80 times more energy per kilogram than a lithium-ion electric vehicle battery. It holds 250 times more energy than a common lead-acid battery. So, it's a no-brainer. Batteries can't possibly deliver the energy needed to power the future of the auto industry, right?

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gimmelotsarobots (author)westfw2008-05-08

This company obviously did no research. It's not jus the battery.

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Plus they were going by weight.

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westfw (author)gimmelotsarobots2008-05-08

The article wasn't by a "company"; it was an engineering survey. When the multiplier is 250, the details you mention are a bit academic. All current electric cars survive by having a range far smaller than an equivalent sized liquid fueled car. For the cases where that reduced range is within what the consumer needs (urban environments, commuter vehicle, etc), including allowances for traffic congestion and etc, that may be fine and electric vehicles might be a good idea. For cases where the range ISN'T enough, electric cars are essentially unusable. AFAIK, conversions are not among the electrical vehicles with leading ranges, and adding more (conventional) batteries isn't a huge help, since the extra room and weight tends to reduce range even while the added batteries would increase it.

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Patrik (author)westfw2008-05-09

You do save a bunch on engine weight though - not enough to make up for the battery weight, but it does make that 250x a lot more bearable.

As for the future of the auto industry... eventually $ per mile is going to be a more important consideration than energy per kilogram...

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westfw (author)Patrik2008-05-09

"Eventually" energy in the form of electricity out of your wall is going to go up dramatically in price as well, unless Something Is Done. Especially if everyone starts using electric cars; supply and demand, after all, and the supply is already somewhat strained. I'm a little surprised that the current difference in price is large enough to make such conversions seem worthwhile. (Of course, if your major car usage is commuting to work, and you can get your employer to pay for half of your energy via "at work electric car charging", I guess that'll work out to be a good deal for quite a while.) In addition to the battery/range issue, I'm not convinced that electric cars even scale well without changes in the electrical generation infrastructure. IIRC, electric cars were originally a solution aimed more at pollution problems than energy conservation. And I don't like solutions that only "help" in limited timeframes due to artificial conditions...

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Patrik (author)westfw2008-05-09

True enough. There are three fundamentals that do play in EV's favor though:

1) Eventually, petroleum products will become a rare commodity. There's plenty of disagreement on when this will actually happen, current oil prices notwithstanding. Alternative fuels would get around this issue though.

2) Capturing exhaust gases centrally may outweigh electricity transmission and storage costs.

3) As battery technology improves, and as people reevaluate their transportation habits (due to rising energy costs), the current energy storage advantage of liquid fuels will become less and less of an issue.

Personally, I'm disappointed that public transportation is being virtually ignored, as compared to all the hubbub around hybrid or electric *personal* vehicles. The current administration may seem like it's trying to do something about the energy issue, but really what they've done is take the focus away from saving energy, towards finding ways to generate more energy.

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gimmelotsarobots (author)westfw2008-05-09

Still, gas prices don't make having a gas car worth it to me. Sure there is more range, but I don't agree with them saying that electrics won't drive the future.

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yourcat (author)2008-05-08

Which batteries were you looking at? Lithium? AGM?

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yourcat (author)yourcat2008-05-08

And which motor is that? Netgain WarP (blank) inch?

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LinuxH4x0r (author)2008-05-07

I am also doing an ev. Lets collaborate on this. I was thinking of using normal car batteries and it came to only $600.

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CameronSS (author)LinuxH4x0r2008-05-07

As 7up said, only deep-cycle batteries will work. I have heard many stories of people who needed new batteries for their EVs who decided to save money by going to Wal-Mart. They bought the deep-cycle batteries they needed, and they worked well at first. After six months they wouldn't take a charge. A normal lead-acid battery pack should last years.

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LinuxH4x0r (author)CameronSS2008-05-07

You have an ev, right? I'll ask you if I need more help Thanks!

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CameronSS (author)LinuxH4x0r2008-05-07

Well, technically, my they are my dad's, my dad's, and my mom's, but sure. ;-) Actually, I'm the president of the Kansas City Mid-America Electric Automobile Association. We were all at lunch when someone decided that it would look good on my resume, so I was unanimously elected.

We have a Ford Courier EV that is kinda-sorta mine, but I never drive anywhere, and officially it's still Dad's. We recently got a Volkswagen Rabbit Truck that's electric, and it may end up being mine, as my dad's still not sure which one he prefers. My mom also has a Zap Xebra SD on which we are still awaiting delivery-the one we got in October had a defective battery and brake system, so they shipped us a new one from California. It's still hanging out in Leavenworth being tested by the dealer.

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guyfrom7up (author)LinuxH4x0r2008-05-07
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LinuxH4x0r (author)guyfrom7up2008-05-07

I assumed that. Thanks for the tip.

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guyfrom7up (author)LinuxH4x0r2008-05-07

when I wanted to build an electronic go-cart (last summer) I almost bought the wrong type of batteries. I got bored with the project before I spent any money (yay)

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Patrik (author)2008-05-07

Yeah, battery technology - capacity, weight and price - is still the primary obstacle in making electrical vehicles mainstream. $3000 sounds fairly reasonable - you may still be able to shave some off of that, but I wouldn't necessarily expect a drastically cheaper solution. As the guy from the corner store mentioned - focus on eliminating as much weight as possible. That converted "heavy-as-can-be Camaro" probably had a bunch of weight stripped out, and/or a high-end $10K+ battery pack installed. You may also want to re-evaluate what you mean by "a day's power". For example, if you were to use this car to commute to work, you'd really only need 1/2 a day's power, because you could recharge during the day...

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guyfrom7up (author)2008-05-07

you pretty much need car batteries to make the AH affordable. Make sure you get deepcycle batteries. Try and lighten your car up as much as possible, it'll do wonders.

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user

battery prices are the only problem i am having.

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