About a month ago, we spoke with Dr. Prabhakar Patil of Compact Power, Inc. about CPI's lithium-ion battery technology. We didn't want to miss the chance to chat in person during the SAE Congress this week, so we stopped by the CPI booth. The reason most AutoblogGreen readers would be following the fortunes of CPI is the company's work with GM on the Chevy Volt (CPI, along with A123 Systems, are supplying the test battery packs for the Volt. BTW, the Volt/Malibu mules are on the track) but Dr. Patil again mentioned that CPI is working with other, unnamed OEMs. We're anxious to learn more about that.

But let's talk about the battery deal we do know about. Based on the packs currently being tested in the Volt, Dr. Patil estimated that a li-ion battery that could move an electric car 100 miles between charges would weigh about 800 pounds. This is double what the Volt's batteries weigh, but would get you 2.5 times the Volt's EV-only distance, because the Volt's batteries reserve some power for the hybrid operations. Regenerative braking can get you the rest of the way. Considering all the studies that show that most people drive well-under 50 miles a day, carrying around all that extra weight for capacity that won't often get used doesn't make a lot of sense, he said. Patil also sees the benefits of the recent CARB ZEV mandate decision. Give a listen.



In the CPI booth was the company's ER2 racer which was setting speed records back in 2002. The ER2 uses an 11 kWh li-ion battery pack and a 165 kW AC induction motor to go from 0-60 in 3.2 seconds. More details here.

The other day, Dr. Prabhakar Patil of Compact Power, Inc. was up in Vancouver, BC for the Auto FutureTech Summit. While AutoblogGreen wasn't able to attend the show, we did get a hold of Dr. Patil on the phone for about 15 minutes to talk about CPI's lithium ion batteries and get Dr. Patil's perspective on what the future holds for electric drive cars. As many readers probably know, CPI is one of the companies delivering batteries to GM for the Chevy Volt, so Dr. Patil is in the center of the lithium ion world. CPI is also working with other automakers (details are still secret, unfortunately).

You can listen to Dr. Patil using the audio widget below and we'll have there is a transcript of the discussion pasted after the jump later today now.