By on May 31, 2012

While on the Infiniti JX launch event, I met a gentleman who now works with Nissan. He had a number of interesting stories about his tenure at GM, and what it was like to work on the EV1 program, as well as the technology that he swears was the forerunner to the Chevrolet Volt.

According to him, GM engineers in 1991 needed a way to keep the batteries in their GM Storm EV mules charged. A crude range extender was fashioned out of a Honda generator, which would kick in when the batteries dropped below a certain point.

The Storm mules were gutted and filled with batteries and a generator and driven around during development. He swears that, with the number of EV1 and Impact (the original GM EV) people left kicking around for the Volt’s development, the range extender idea must have lived on in someone’s mind for a very long time, until it came time to put it in operation.

I begged him to grant me an interview, or at least let me quote him, but he wouldn’t indulge me. I was left wondering about the early days of the program, until I stumbled upon this article in the January 1992 edition of Motor Trend. The big difference here is that GM has ditched the range extender and worked out a proper 220V charging system (apparently that was an obstacle in the early days).  Note that the EV1 charging paddle is absent here, and it seems to use a very-1990s flashing LED charge port, similar to the L.A. Gear running shoes that were found to have mercury in them.

Since there seems to be a fair amount of Storm love on TTAC these days, it’s worth recognizing the irony of a largely forgotten car paving the way for perhaps the biggest automotive lightning rod since the Edsel.

You can see the full-size scan in the gallery below


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24 Comments on “Geo Storm EV Mule, The Chevrolet Volt’s Baby Daddy?...”

  • avatar

    Could you banish celebrity journalism argot from TTAC? If I see baby mama, baby daddy, or baby bump one more time I’m going to do some serious cookie tossing.

  • avatar

    Who reads a 1992 C&D magazine in 2012. LOL, I know you guys are journalists and all, I applaud your dedication for doing research but…. bahhh….I just picture you guys sitting around looking at 20+ year old magazines digging up articles and drinking, and I’m not talking coffee. I don’t even have my adult collection from that era anymore.

  • avatar


    My comment was in no way intended to reflect on the substance of this post. I agree with you about the substance.

  • avatar


    As a professional writer for a wide range of publications including Smithsonian and The Atlantic, I have strong feelings about usage. However, my comment was in no way intended to reflect on the substance of this post. I agree with you about the substance.

  • avatar

    I find the most interesting part is this was all going on in 1991. Think about it GM had working mules as early as the Gulf War, and a working EV by I believe 1997. Granted these feats were all squandered later but still its quite impressive they were this deep in the game when they were.

    • 0 avatar

      I recall being behind an EV1 on the ramp from SB I75 to WB I696, and that sucker handily out-accelerated my V6 Contour!

    • 0 avatar

      The EV1, AKA Impact, was actually the brainchild of Paul MacCready, who founded Aerovironment, and who was also the brains behind the Gossamer Condor and the Gossamer Albatross, the first and second human-powered aircraft. Both won major prizes, the Albatross after Bryan Allen pedaled it across the English Channel in several hours, in 1977. I know they had examples working at least as early as ’91. I saw an Impact that early. MacCready recently died, but I would imagine there ***might*** be people at Aerovironment who could flesh out the early history and role of the storm. Or who could point someone to the right people (perhaps formerly) at GM.

    • 0 avatar

      In ’91, GM (and anybody else working on EVs) had the same problem they have today; batteries don’t store enough power for their mass and bulk and they cost a lot. Except in ’91 it was worse.

      • 0 avatar

        That’s a rather pessimistic view of looking at it. The fundamental problems are the same, but the technology has improved dramatically.

        In terms of battery weight: 6x in 20 years, 4x in 13 years.
        GM Storm (1991), Impact (1994), EV1 Gen 1 (1996) – advanced lead acid, ~40 Wh/kg
        GM EV1 Gen 2 (1999) – Ovonics NiMH, ~60 Wh/kg
        GM Volt (2010) – LG NMC lithium-ion, ~160 Wh/kg (IIRC)
        Tesla Model S (2012) – Panasonic lithium-ion, ~240 Wh/kg

        While the EV1 was hugely innovative and offered reasonable range (given the low-weight aero-first 2 seat design), it’s very unlikely that it could have been offered for sale at reasonable prices at the time. Ask Honda how well high-efficiency expensive 2 seat cars sell.

        In 20 years battery technology has advanced from unconventional prototypes made out of unobtanium to relatively conventional production vehicles with relatively mainstream styling/layout and relatively accessible pricing.

  • avatar
    schmitt trigger

    Around the same time, GM’s Electro Motive Division was succesfully replacing the DC motors in locomotives with AC-induction motors.

    The latter motors are lighter, cheaper and essentially maintenance free. Of course to power an AC motor requires a far more complex electronic brain which drive an equally substantial electronic power train…no small feat in the early 90s!

    I wonder how much of EMD’s expertise was used by Chevrolet? Of course in locomotives, the power devices were either thyristors or IGBTs, whereas on a car you had to use the smaller and less expensive Mosfets.

  • avatar

    Sometimes, I wonder what would have happened if GM had not killed off the EV1 program.

    Would we have something far more advanced than the Volt at this point? I doubt it due to two important factors:

    1. The price of gas.

    Periods of stable gas prices interrupted by short bursts of rising gas prices. Eventually, they stabilize.

    2. Battery technology

    The battery technology available back then was not as powerful or efficient as what we have now. Even so, current technology must evolve at a rapider rate to keep up with the demands of the marketplace.

    I wish you could have gotten that interview as well. I’m wondering if this person was sworn to secrecy past a certain point?

    • 0 avatar

      Definitely battery technology. Even now, EVs are doomed to be a niche unless and until there is some sort of major breakthrough. As much as I respect MacCready–a brilliant, thoughtful man–the Impact/EV1 was premature.

      • 0 avatar

        actually battery technology has been up to 90% efficient for the past 50 years or so,the actual problem is the maintenance involved with efficient batteries.
        the mos efficient variety is still the good old lead acid battery it will retain 80-90percent efficiency for about 7 years in a deep cycle use,without any memory effects.
        NIMH batteries are usually around 65-70% efficient and have terrible memory issues if not fully discharged regularly in most applications.
        lithium ion batteries are around 60-65% efficient and have very little memory issues and are usually good for around 4-5 years regardless of cycle usage.
        The problems are that people want batteries that dont leak and dont need to be refilled with water weekly.
        If people were willing to do a little maintenance the 350 mile to a charge car is easily and inexpensively possible.
        forklifts and mining equipment have been working full out for 8 hour shifts on an 8 hour charge for a very long time but…it takes some maintenance.

    • 0 avatar

      My uncle to this day won’t talk specifically about what he was doing at NASA in the 70s due to such agreements, but over the years has made vague comments and references about cloning and ETs.

      • 0 avatar

        Now obviously I know nothing about your uncle, but I can say this with certainty, had I been working at NASA with any kind of security clearance I’d probably make those kinds of vague comments too just for s**ts and giggles.

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