Here's a hot topic for discussion. Is battery technology really holding up widespread use of Plug-In Hybrids like the Volt? In 1998 GM put Nickel-metal-hydride batteries in the EV1 and suddenly a 50-60 EV became a 125-150 mile EV. Then they added an onboard generator, cut the all-electric range back down to 40 miles, and showed this EV1 variant at the 1998 Detroit Auto Show.

A 40-mile Plug-In hybrid only needs a little over 400lbs of NiMH batteries, so the only reason we would need a better battery is to get 100+ mile all-electric range. But I don't need 100-miles and don't want to pay for or haul around all those batteries. Would he keep me in a 20 MPG car instead of a 150MPG car for another 5 years just because I need a crutch (the on-board generator) for my own peace of mind?!?"

What John McCain should do with that $300 million is use Eminent Domain to seize Chevron's patent rights to NiMH batteries and make this formula public property. Chevron paid $160 million and have not profitted anywhere near that much from these rights, so $300 million is way more than it's worth considering there is only 7 years left on these patents.

For a long-range (100+ miles) EV, 1000 lbs of batteries is hard to design a car around, but for a 40-mile plug-in, NiMH is a great battery and has now been proven in all weather conditions, Toyota, Ford and Honda have never had to replace a NiMH pack under warranty and several Prius' now have over 300,000 miles on their original NiMH packs. Let's get over batteries, and get these PHEVs built!

Dr Mark

A 40-mile Plug-In hybrid only needs a little over 400lbs of NiMH batteries.

For a long-range (100+ miles) EV, 1000 lbs of batteries is hard to design a car around, but for a 40-mile plug-in, NiMH is a great battery and has now been proven in all weather conditions, Toyota, Ford and Honda have never had to replace a NiMH pack under warranty and several Prius' now have over 300,000 miles on their original NiMH packs. Let's get over batteries, and get these PHEVs built!

Dr Mark

Actually 400 lb of the PEVE EV-95 NiMH batteries would give a range of 60 miles.

I do not think 1000 lb of batteries is hard to design a car around. Toyota modified an existing car (mini SUV) and had no problem making the RAV4-EV. Battery placement gives options that 1000 lb of ICE engine placement does not.

Considering that the we're spending almost $450 million per day in Iraq, McCain's so-called $300 million battery challenge is a joke.

Considering that in 2003, the maximum Federal Tax Credit for the purchase of a vehicle with a GVW of 6,000 lbs or greater was $100,000;
A $5,000~$7,000 Federal Tax Credit for a Serial Plug-In Hybrid like the Volt is also a joke.

Its obvious that big oil won't go down without a fight.
They captured Nickel Metal Hydride batteries so as to prevent them from being used in pure BEV's & Hybrids, and with their life-partners the car companies, they've made every effort to prevent increases in fuel economy standards.
Pride goeth before the fall.

I do not think 1000 lb of batteries is hard to design a car around. Toyota modified an existing car (mini SUV) and had no problem making the RAV4-EV. Battery placement gives options that 1000 lb of ICE engine placement does not.

Really??? You must know something car markers mist. I would run and apply for a job there if I was you.:eek:

On a more serious note, well it is good to know even Republicain are starting to open their eyes, now is it a good news? I would personnaly prefer to see that money channel through Universities and Research center, the money would do more then simply suger coated the car industry. BTW, most high performance battery like A123 actually come from University spin off. Money generated by the IP (Intellectual Properties) would then be reinjected in R&D.

Really??? You must know something car markers mist. I would run and apply for a job there if I was you.:eek:


It has already been done.
GM EV-1 1300 lb lead/acid; 1000 lb NiMH
Toyota RAV4-EV 1200 lb lead/acid; 1000 lb NiMH
Ford RangerEV 1200 lb lead/acid;900 lb NiMH

Like I said, it can't be that hard. The auto makers have already done it.

Really??? You must know something car markers mist. I would run and apply for a job there if I was you.:eek:

On a more serious note, well it is good to know even Republicain are starting to open their eyes, now is it a good news? I would personnaly prefer to see that money channel through Universities and Research center, the money would do more then simply suger coated the car industry. BTW, most high performance battery like A123 actually come from University spin off. Money generated by the IP (Intellectual Properties) would then be reinjected in R&D.

Dear FrankyB,
Oh sure, University research is a tried and true tactic to drop the price of oil. If you start a University research program next year you MIGHT see commercialization of the resulting IP (if there is any) by 2015 but more likely 2025. The U.S. economy will be on a par with Malaysia by then.

Research is good, but we are 10 years overdue capitalizing on the research that resulted in the 1996 breakthrough in large format NiMH batteries. What good is research and innovation if the results just sit in a library? And since Chevron is not capitalizing on this technology, it's time for the government to help, either by the USPTO challenging the blocking of NiMH technology, or buying the patent rights for public use of the NiMH patents, or purchasing 100,000 batteries a year, (and adding another 100,000 each year) from Cobasys for use by EV manufacturers, or how about converting all Federal and military vehicles to series hybrid.

When the EV revolution is finally underway, the profits will fund lots of University research and scholarships not to mention the additional $500 billion/year that will stay in the U.S. so parents may actually have the money to PAY for college.

It has already been done.
GM EV-1 1300 lb lead/acid; 1000 lb NiMH
Toyota RAV4-EV 1200 lb lead/acid; 1000 lb NiMH
Ford RangerEV 1200 lb lead/acid;900 lb NiMH

Like I said, it can't be that hard. The auto makers have already done it.

Thanks Will, I wasn't sure what the NiMH packs in the EV1 weighed. The increase from 60 miles to 130 miles electric range means those batteries gave the EV1 a power-to-weight advantage of 2.8-to-1. For me, that tips the scales for PHEV applications (although I'd go with a 20 mile lead-acid PHEV if someone made it).

Nickel is up to $9.75/lb, but if we had a growing auto industry maybe investors would lose interest in driving up commodity prices. But as of today 300lbs of battery should be under $5000. That's why a PHEV with $5000 of batteries is so much more appealing than a full EV with $20,000 of batteries.

Dear FrankyB,
Oh sure, University research is a tried and true tactic to drop the price of oil. If you start a University research program next year you MIGHT see commercialization of the resulting IP (if there is any) by 2015 but more likely 2025. The U.S. economy will be on a par with Malaysia by then.

Research is good, but we are 10 years overdue capitalizing on the research that resulted in the 1996 breakthrough in large format NiMH batteries. What good is research and innovation if the results just sit in a library? And since Chevron is not capitalizing on this technology, it's time for the government to help, either by the USPTO challenging the blocking of NiMH technology, or buying the patent rights for public use of the NiMH patents, or purchasing 100,000 batteries a year, (and adding another 100,000 each year) from Cobasys for use by EV manufacturers, or how about converting all Federal and military vehicles to series hybrid.

When the EV revolution is finally underway, the profits will fund lots of University research and scholarships not to mention the additional $500 billion/year that will stay in the U.S. so parents may actually have the money to PAY for college.

Don't twist what I said, and again A123 started from the University, Google too... I mean really... :confused:

Thanks Will, I wasn't sure what the NiMH packs in the EV1 weighed. The increase from 60 miles to 130 miles electric range means those batteries gave the EV1 a power-to-weight advantage of 2.8-to-1. For me, that tips the scales for PHEV applications (although I'd go with a 20 mile lead-acid PHEV if someone made it).

Nickel is up to $9.75/lb, but if we had a growing auto industry maybe investors would lose interest in driving up commodity prices. But as of today 300lbs of battery should be under $5000. That's why a PHEV with $5000 of batteries is so much more appealing than a full EV with $20,000 of batteries.

The battery ranges were: faulty Delco batteries (50-60 miles), Panasonic PbA (90-110), and inferior Ovionics batteries GM used (EPA certified 140). That is why Lutz keeps saying the range for the EV-1 was only 60 miles. The current price for the NiMH batteries should be around $12,500 if they were being made. That is for a PHEV-100 not a PHEV-40 like the Volt. Since the Ovionics 9500 battery and the PEVE EV-95 battery is no longer being sold, who knows what they cost.

The battery ranges were: faulty Delco batteries (50-60 miles), Panasonic PbA (90-110), and inferior Ovionics batteries GM used (EPA certified 140). That is why Lutz keeps saying the range for the EV-1 was only 60 miles. The current price for the NiMH batteries should be around $12,500 if they were being made. That is for a PHEV-100 not a PHEV-40 like the Volt. Since the Ovionics 9500 battery and the PEVE EV-95 battery is no longer being sold, who knows what they cost.

So our numbers agree almost to pound and to the penny. I estimated under $5000 for a NiMH pack for the Volt, and the weight would be about 400lbs. So what if the Lithium pack is 100lbs less (no numbers on this yet). Collectively my family could stand to lose 100 lbs, so its a wash for me. Let's build this thing.

But the sad reality is that GM used to own the rights for NiMH but sold them to Chevron. I'm sure part of that transaction was to sign in blood that they would never use "nickel-metal anything" batteries in a car. So, for GM NiMH is probably not possible. But Toyota might end up with NiMH in their plug in ( http://www.boston.com/business/globe/articles/2007/07/26/toyota_plug_in_hybrid_hits_the_road/ ). Then we'd get a real comparison.

You guys talk even more than university researchers. If it isn't that hard, why haven't YOU built yourself a PHEV already? You say that there's plenty of off-the-shelf technology out there. There's plenty of profit to be made. What's holding you up? Geez, enough with the conspiracy theories and build one already. And while you're at it, build two. If it's as good as you claim, I'll be your first customer!

Research is good, but we are 10 years overdue capitalizing on the research that resulted in the 1996 breakthrough in large format NiMH batteries. What good is research and innovation if the results just sit in a library? And since Chevron is not capitalizing on this technology, it's time for the government to help, either by the USPTO challenging the blocking of NiMH technology, or buying the patent rights for public use of the NiMH patents, or purchasing 100,000 batteries a year, (and adding another 100,000 each year) from Cobasys for use by EV manufacturers, or how about converting all Federal and military vehicles to series hybrid.

The original NiMH technology was not a winner. Cobasys, the spinoff from the earlier EV1 c venture, is close to financial ruin. GM has the option of bailing/buying them out. See http://www.thetruthaboutcars.com/moneybags-gm-to-buy-cobasys/.

You guys talk even more than university researchers. If it isn't that hard, why haven't YOU built yourself a PHEV already? You say that there's plenty of off-the-shelf technology out there. There's plenty of profit to be made. What's holding you up? Geez, enough with the conspiracy theories and build one already. And while you're at it, build two. If it's as good as you claim, I'll be your first customer!

I do not have the tools, location, or the time. I am getting ready to have it done on my behalf. My specs:

1 ton streach van (E-350 or equivalent)
4 160HP hub motors (PML)
40 kW genset ( I will need that when I am hauling a 10,000 lb trailer)
batteries open (would like PEVE EV-95 NiMHs, but not available until 2015)

I'll leave the 35 gal fuel tank and use butanol instead of gas. Should have to fill it up about twice a year depending on how many times I have to tow the trailer.

You guys talk even more than university researchers. If it isn't that hard, why haven't YOU built yourself a PHEV already? You say that there's plenty of off-the-shelf technology out there. There's plenty of profit to be made. What's holding you up? Geez, enough with the conspiracy theories and build one already. And while you're at it, build two. If it's as good as you claim, I'll be your first customer!

Dear First Customer (Herman),
I HAVE converted a Toyota MR2 to a series-hybrid; so I know what I'm talking about. This would be a cakewalk for a car company. I went cheap with 26 spiral wound lead-acid batteries and in quantity-1 of everything else it cost me $10,000 on top of a $10,000 car (selling the engine for $1500 and various parts for $100 more did help). If I wanted to be a pioneer I could put 9 NiMH Vectrix motorcycle batteries in it for an additional $10,000 and double my 20 mile range but my real interest is to refine the on-board generator, since this is the trickiest part. You can already buy everything else you need for an EV conversion (some good links on my website http://www.freedomformula.org ), but not so easy for a do-it-yourself series-hybrid PHEV conversion. So if you want to be my first customer contact me through our website. The 12kW genset should be perfected in a month and we're hoping to get 100mpg in the MR2 (currently gets 68 with a stock Briggs&Stratton).

Back to our main thread though, with proven batteries like NiMH, GM wouldn't be taking any risk at all; They've already DONE it (Gee, I hope they didn't destroy the drawings and computer code too). The reason the EV1 failed is the profit margin wasn't there, but after you cut out 75% of the batteries it would have been a big money maker. They could cut down on performance quite a bit too, since the EV1 could do 183MPH WITH 1000lbs of batteries. Imagine what it could do with 250lbs of batteries plus a 100lb genset! But, aw shucks I guess we can't test this out because GM CRUSHED THEM.

I am trying real hard to stay positive; I do really like the Volt, I just wish we were cheering GM on from the seats of our EV1 PHEVs.

The original NiMH technology was not a winner. Cobasys, the spinoff from the earlier EV1 c venture, is close to financial ruin. GM has the option of bailing/buying them out. See http://www.thetruthaboutcars.com/moneybags-gm-to-buy-cobasys/.

Of course Cobasys is near financial ruin. They have very little production and refuse to sell their products to willing buyers. I called and wanted a quote on 30 of the 9500 batteries listed on their website and was told unless I wanted to order 10,000, they were not interested. What a bunch of idiots.

Of course Cobasys is near financial ruin. They have very little production and refuse to sell their products to willing buyers. I called and wanted a quote on 30 of the 9500 batteries listed on their website and was told unless I wanted to order 10,000, they were not interested. What a bunch of idiots.

Who is Cobasys and why would they tie up use of NiMH batteries? It seems other people are making them? I have a friend who owns a Rav4-EV and those NiMH batteries (with over 100,000 miles on them which unlike the Volt will experience, get full discharge use) were made by Panasonic (maybe Panasonic had to license battery patents from Chevron, I don't know?). Does anyone know who makes the rest of the NiMH batteries used in hybrids; doesn't seem that Cobasys is even in that market (maybe that's why they are going broke)?

I have another friend who owns a Vectrix motorcycle and its NiMH batteries are made by a Hong Kong company named Goldpeak; so here's an interesting question, since Hong Kong is Communist China, can Chevron enforce their patents on them? Microsoft has a hard time with that. Wouldn't it be ironic if China becomes the world's supplier of NiMH batteries due to the way we regulate ourselves into a box and tie our own hands; it's kind of like China drilling for oil off Cuba into the same reserves that Charlie Crist and Mel Martinez won't allow Americans to drill. OK, that does it, that's great fodder for a new thread.

Here's a hot topic for discussion. Is battery technology really holding up widespread use of Plug-In Hybrids like the Volt? In 1998 GM put Nickel-metal-hydride batteries in the EV1 and suddenly a 50-60 EV became a 125-150 mile EV. Then they added an onboard generator, cut the all-electric range back down to 40 miles, and showed this EV1 variant at the 1998 Detroit Auto Show.

A 40-mile Plug-In hybrid only needs a little over 400lbs of NiMH batteries, so the only reason we would need a better battery is to get 100+ mile all-electric range. But I don't need 100-miles and don't want to pay for or haul around all those batteries. Would he keep me in a 20 MPG car instead of a 150MPG car for another 5 years just because I need a crutch (the on-board generator) for my own peace of mind?!?"

What John McCain should do with that $300 million is use Eminent Domain to seize Chevron's patent rights to NiMH batteries and make this formula public property. Chevron paid $160 million and have not profitted anywhere near that much from these rights, so $300 million is way more than it's worth considering there is only 7 years left on these patents.

For a long-range (100+ miles) EV, 1000 lbs of batteries is hard to design a car around, but for a 40-mile plug-in, NiMH is a great battery and has now been proven in all weather conditions, Toyota, Ford and Honda have never had to replace a NiMH pack under warranty and several Prius' now have over 300,000 miles on their original NiMH packs. Let's get over batteries, and get these PHEVs built!

Dr Mark


Hey Dr. Mark,

I just took this info onto another board and got slammed by someone saying the NiMH is available from 2 companies other than Cobasys-Chevron, namely Electro Energy Inc. and Nilar Inc. They get outside of the patent becaust the internal configuration is slightly different. You know anything about this?

I come here to be educated then I take what I learn here to people who don't think there's anyway off of gasoline.

Also, is there anyway I can have an existing car converted to battery or hydrogen without it costing an arm and a leg or turning my car into a bomb on wheels?

You guys talk even more than university researchers. If it isn't that hard, why haven't YOU built yourself a PHEV already?

Many have. My associate, Ricardo Bazzarella, even built a business around it. Granted it's based on a pre-existing chassis, but so are many EV builds including my own lithium ion 28.2KwH car.


But the sad reality is that GM used to own the rights for NiMH but sold them to Chevron.

GM recently announced buying them back.

Many have. My associate, Ricardo Bazzarella, even built a business around it. Granted it's based on a pre-existing chassis, but so are many EV builds including my own lithium ion 28.2KwH car.



GM recently announced buying them back.

Can you give me a few links on GM buying back the NiMH? I've looked and can't find anything on it. Thanks.

Roger881,

http://www.crainsdetroit.com/apps/pbcs.dll/article?AID=/20080605/REG/844712730&template=printart

http://www.thetruthaboutcars.com/mon...o-buy-cobasys/

Many have. My associate, Ricardo Bazzarella, even built a business around it. Granted it's based on a pre-existing chassis, but so are many EV builds including my own lithium ion 28.2KwH car.

GM recently announced buying them back.

SOooo.. if GM now has the NiMH batteries back they don't have to wait for the Volt! Take a look at the "EV1 Drivetrain Prototypes" in this Wikipedia Article. They HAD a 40-mile PHEV running IN A PRODUCTION CAR 10 years ago. How long can it take to get DOT approval on an engine variant of a car that was already approved for use in California (by the way GM; stay away from California with this car, they'll tie you up in regulations; bring it to Florida instead, we don't have vehicle safety OR emissions inspections).

http://en.wikipedia.org/wiki/General_Motors_EV1

GM said there was no market for that car! Now that they are on the verge of bankruptcy and gas is headed for $5/gal, I think the market has ARRIVED. So I hope they have the brains to just build the 40-mile version of the EV1. I'd like mine in electric blue please, and I prefer the turbo-diesel generator. See you at the showroom in 3 months.

Sincerely Dr Mark

Roger881,

http://www.crainsdetroit.com/apps/pbcs.dll/article?AID=/20080605/REG/844712730&template=printart

http://www.thetruthaboutcars.com/mon...o-buy-cobasys/

The second link has been removed and the first just says they are talking! Has it happened yet?

Here's a chance for John McCain to reach into the Bush administration and prove he's willing to get things fixed. How about some of that $300 million battery prize going to make a 45 amp-hour NiMH for a 2009 GM car.

Who is Cobasys and why would they tie up use of NiMH batteries? It seems other people are making them? I have a friend who owns a Rav4-EV and those NiMH batteries (with over 100,000 miles on them which unlike the Volt will experience, get full discharge use) were made by Panasonic (maybe Panasonic had to license battery patents from Chevron, I don't know?). Does anyone know who makes the rest of the NiMH batteries used in hybrids; doesn't seem that Cobasys is even in that market (maybe that's why they are going broke)?

I have another friend who owns a Vectrix motorcycle and its NiMH batteries are made by a Hong Kong company named Goldpeak; so here's an interesting question, since Hong Kong is Communist China, can Chevron enforce their patents on them? Microsoft has a hard time with that. Wouldn't it be ironic if China becomes the world's supplier of NiMH batteries due to the way we regulate ourselves into a box and tie our own hands; it's kind of like China drilling for oil off Cuba into the same reserves that Charlie Crist and Mel Martinez won't allow Americans to drill. OK, that does it, that's great fodder for a new thread.

Cobasys is a joint venture between ECD (actual patent holder) and Chevron. Chevron owns 60%. Cobasys controls worldwide licensing for the NiMH patents. There are only 2 companies in the world licensed to manufacture NiMH batteries over 20AH for transportation use. One is Saft in France and the other is Goldpeak. Goldpeak can not manufacture cells in excess of 30AH or the cells must remain in Asia. Saft can not export the cells out of Europe, Africa, and the Middle East. The PEVE EV-95 batteries in your friend’s Rav4-EV were manufactured in spite of the patents while GM controlled them. They were later sued by Chevron and can no longer make them except for warranty replacement in the Rav4s until 2015. Since all of the Rav4-EVs are now out of battery warranty, se la vie.

Hey Dr. Mark,

I just took this info onto another board and got slammed by someone saying the NiMH is available from 2 companies other than Cobasys-Chevron, namely Electro Energy Inc. and Nilar Inc. They get outside of the patent becaust the internal configuration is slightly different. You know anything about this?

I come here to be educated then I take what I learn here to people who don't think there's anyway off of gasoline.

Also, is there anyway I can have an existing car converted to battery or hydrogen without it costing an arm and a leg or turning my car into a bomb on wheels?

Both Nilar and EEI are working inside the licensing. They are using 9AH and 6AH cells respectively. The fact that these cells have no use in an EV is why they can manufacture them. You would have to install 10 parallel strings of cells to keep the discharge rate down in an EV. Then you would have one heck of a time trying to charge all 10 strings and keep them balanced. The cost would be more than lithium batteries and the weight would be more than lead.

The second link has been removed and the first just says they are talking! Has it happened yet?

Here's a chance for John McCain to reach into the Bush administration and prove he's willing to get things fixed. How about some of that $300 million battery prize going to make a 45 amp-hour NiMH for a 2009 GM car.

Most people do not think about this, but you would have a hard time with 45AH batteries in a car. The reason is that you can not discharge most batteries over a 2C rate. That means you are limited to 90A at what ever voltage you have setup in the car. If you had 1000V, then 90A would give you enough for a 85kW traction motor. I am guessing about the efficency of the controller, but you get the point. It would be bad if you fried the batteries while you were accelerating to get on the freeway. Even most lithium chemestries are only rated for 30 seconds at 2C discharge.

Most people do not think about this, but you would have a hard time with 45AH batteries in a car. The reason is that you can not discharge most batteries over a 2C rate. That means you are limited to 90A at what ever voltage you have setup in the car. If you had 1000V, then 90A would give you enough for a 85kW traction motor. I am guessing about the efficency of the controller, but you get the point. It would be bad if you fried the batteries while you were accelerating to get on the freeway. Even most lithium chemestries are only rated for 30 seconds at 2C discharge.

The guy who designs the battery management system for the Vectrix motorcycle is a friend of mine and they have been using a 30-AH NiMH pack (made by Andrew Ng who owns Goldpeak Batteries in Hong Kong; Goldpeak licensed NiMH from Ovonics before Chevron acquired the patents, and a pre-existing license remains with a patent when sold, so Goldpeak is allowed to make large format NiMH batteries, but when Panasonic tried it, Chevron sued, I believe specifically over the Rav4 EV batteries). The 30AH NiMH pack can deliver 120 Amps during hard acceleration but they limit it to about 80A to maximize range. So your figure of 2C is a bit low, but you are right on about the importance of the "power density" spec. Apparently higher power density is possible with NiMH since the new Porche hybrid drives a 46HP (34kW) motor with a 3.5A-hr NiMH pack.

So the size of the battery pack doesn't just affect your range per charge, it affects lots of performance specs even in the first mile you drive. If the battery pack is too small you can't drive a high performance motor, and since batteries are even more limited on charge current than on discharge current you get less effiiciency during regenerative braking. So a 10-mile range PHEV is probably not a great idea because you'll constantly be charging and discharging above 10C, but for a 40-mile PHEV you're down to 2-3C and the batteries are happy. For many reasons, I really like GMs concept for the Chevy Volt; of course, what really bugs me is that they had already built it in 1998 (a 40-mile series hybrid version of the EV1).

I chose spiral wound sealed lead-acid batteries (17AH) for my MR2 project. They do fine with a 10C discharge rate in short bursts and I get about 6C back in on regeneration. There's a useful chart comparing battery technologies in the lower right corner of this page:

http://serieshybrid.com/FreedomFormula/images/Effic.htm

The guy who designs the battery management system for the Vectrix motorcycle is a friend of mine and they have been using a 30-AH NiMH pack (made by Andrew Ng who owns Goldpeak Batteries in Hong Kong; Goldpeak licensed NiMH from Ovonics before Chevron acquired the patents, and a pre-existing license remains with a patent when sold, so Goldpeak is allowed to make large format NiMH batteries, but when Panasonic tried it, Chevron sued, I believe specifically over the Rav4 EV batteries). The 30AH NiMH pack can deliver 120 Amps during hard acceleration but they limit it to about 80A to maximize range. So your figure of 2C is a bit low, but you are right on about the importance of the "power density" spec. Apparently higher power density is possible with NiMH since the new Porche hybrid drives a 46HP (34kW) motor with a 3.5A-hr NiMH pack.

So the size of the battery pack doesn't just affect your range per charge, it affects lots of performance specs even in the first mile you drive. If the battery pack is too small you can't drive a high performance motor, and since batteries are even more limited on charge current than on discharge current you get less effiiciency during regenerative braking. So a 10-mile range PHEV is probably not a great idea because you'll constantly be charging and discharging above 10C, but for a 40-mile PHEV you're down to 2-3C and the batteries are happy. For many reasons, I really like GMs concept for the Chevy Volt; of course, what really bugs me is that they had already built it in 1998 (a 40-mile series hybrid version of the EV1).

I chose spiral wound sealed lead-acid batteries (17AH) for my MR2 project. They do fine with a 10C discharge rate in short bursts and I get about 6C back in on regeneration. There's a useful chart comparing battery technologies in the lower right corner of this page:

http://serieshybrid.com/FreedomFormula/images/Effic.htm

The most common brand of LiFePO4 batteries for EV use is probably ThunderSky, who produce a range of large prismatic LiFePO4 cells between 40Ah and 1600Ah. Unfortunately due to the inherent design of the large prismatic cells, they typically have trouble providing more than about 3C of continuous current (e.g the 40Ah cells can only put out about 120A continuous). This is quite acceptable for vehicles of modest performance such as commuter vehicles, but high performance electric vehicles really need a pack which can sustain around 10C continuous.

http://zeva.com.au/tech/LiFePO4.php

They've gotten better, but still not 10C. Lead batteries have always been better about high discharges but life is shorter.

How much are the Goldpeak 30AH batteries and what is the size? I've been thinking about them for my E-bike, but can't find any info. It would double my range if I can fit them in the bike.