Coming Soon: Affordable Plug-In Hybrid Conversion Kits

By · June 12, 2008

For a car class numbering less than 200 worldwide, plug-in hybrids are
sure generating a lot of attention, including a Brookings Institution conference
yesterday where Toyota's Bill Reinert added a note of caution to the
rosy predictions of plug-in hybrids right around the corner. Today, the Department of Energy announced a $30 million grant to Ford, General
Motors and General Electric. The DOE's goal is to commercialize plug-in hybrids by 2016. If you can't wait that long, a recent
announcement may be encouraging: Hymotion will soon be offering a plug-in hybrid
conversion kit
for less than $10,000.

Now called A123 Hymotion—reflecting its purchase by battery maker A123 Systems—the company launched its new L5 Plug-In Conversion Module. This supplements the Prius's stock 1.3-kWh nickel-metal-hydride battery pack with a 5-kWh pack based on A123's iron nanophosphate lithium ion cells.

Interestingly, the six initial installers include four Toyota dealerships. They’re in Boston, Los Angeles, Minneapolis, and Washington, DC—the non-dealership installers are Green Gears in San Francisco, and Green Car Company in Seattle. You still have to order the module through the Hymotion website, but Prius owners who want to expand their full-electric running time and juice it up from the wall socket at night can now benefit from one-stop shopping. It’s a “very significant” announcement, said Felix Kramer of plug-in advocacy group Calcars. “Considering a dealer’s main allegiance is to the company, it’s pretty colossal.”

Several features distinguish the new kit from others on the market. For one thing, it's been engineered and crash-tested to meet all applicable federal new-car safety standards. For another, the converted car meets new-car emissions standards—which not every plug-in conversion does, including earlier versions of Hymotion's own kit.

And finally, it costs a lot less than other lithium ion kits. For example, take the conversion offered by Hybrids Plus, of Boulder, Colorado. To get a "PHEV-30," meaning a plug-in with roughly 30 miles of pure electric range, will cost you roughly $30,000 for the 4.5-kWh replacement pack plus another 4.5-kWh auxiliary pack—albeit installed. Those packs, by the way, also use A123's cells.

Hymotion, on the other hand, quotes 30 to 40 miles of "electrically assisted" range for a third of that: $9,995 including installation and a three year warranty. Left unspecified thus far, is the actual distance that the Hymotion kit will run in pure electric mode, without switching on the internal combustion engine. The answer, as always, lies in the car's duty cycle: how heavily it's loaded, how aggressively it's driven, the mix of speeds, and even such factors as how many hills it climbs.

According to Hymotion representative Lizzie Ames, the company isn’t making executives—or indeed anyone—available to the press for comment right now. So we'll leave it to road testers to offer real-world experience. And no doubt the highly active plug-in hybrid community will weigh in, followed—we hope—by some official testing by the likes of Argonne National Labs (who tested the exhaust emissions from a previous iteration of the Hymotion kit). Now, let the marketing begin…

New to EVs? Start here

  1. Seven Things To Know About Buying a Plug-In Car
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  2. Incentives for Plug-in Hybrids and Electric Cars
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  3. Buying Your First Home EV Charger
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