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A123Systems targeting stop-start/micro-hybrid market with 12V Li-ion Nanophosphate Engine Start Battery

Nanophosphate Engine Start Battery (12V): Click to enlarge.

A123 Systems is targeting the emerging stop-start/microhybrid market with a 12V Li-ion battery solution based on its automotive class lithium ion AMP20 20 Ah prismatic pouch cells. The system comes equipped with battery management electronics for cell balancing and protection.

Compared to lead-acid AGM batteries used in such applications, the Li-ion batteries offer better charge acceptance, ultimately resulting in lower alternator loads on the engine and better fuel economy; lighter weight (about 60% less than comparable lead-acid batteries); and longer life, according to Jeff Kessen, A123’s VP of Automotive Marketing and Communication.

In addition to the two posts on the 12V package, the battery has a communication connector to the vehicle controller.

Our approach is a little bit different than the Gaia package that Porsche is using [earlier post]. In that application, they are constrained on the cold for a mainline car manufacturer, that’s not really an option. Our package is still in the 60 Ah to 80 Ah range, depending on the specific design, because we have to have to cold starts. We are really going for direct replacement, not asking [OE’s] to compromise on the performance.

—Jeff Kessen

A123 has had a version of the system in a demanding bus application for almost three years, and is tracking to about 6 years of life, Kessen says. By contrast, AGM batteries in that type of application are lasting 18 months to two years. The additional lifetime of 2.5 to 3x will help offset the higher cost of the Li-ion solution, Kessen says.

The Amp20 cells were designed for plug-in hybrid and electric vehicle applications, and offers a power density of more than 2,400 W/kg and 4,500. Nominal voltage is 3.3V.

A123 Systems currently has production agreements with two automotive OEs. The first, a more conventional SLI application rather than a microhybrid, was what initially pulled A123 into the 12V space, Kessen said. Since then, the company has entered a production contract with a major yet-to-be-named OE on a stop-start system. A123 Systems says that it is also in development with four other vehicle manufacturers.



These would be awesome in a golf cart! Weeee!!!!


"The additional lifetime of 2.5 to 3x will help offset the higher cost of the Li-ion solution..."

There is your marketing value proposition. Over the long haul there is less replacement and loss due to failure.


I'll buy one right now just for the weight savings! I'm playing with a little MR2 I bought and want to eventually convert to electric but don't have time right now. So I'm playing with the aero and the weight to see what difference it makes on the vehicle efficiency.


Interesting battery.

If basic unit voltage was raised to 48 Volts, 10 such units could power a practical BEV, 4 units for a practical PHEV and two units for improved HEVs and one unit for improved stop-start regular ICE.


I like when they do drop in replacements, it is easy to compare with previous units. You can look at size, weight, cost, longevity and other factors.


6 years under stressful conditions, probably 15 years under mild conditions.. the weight savings leading to fuel savings alone will probably pay for them.


If you look at the total weight of hybrid systems, this Stop/Start feature makes a heck of a lot of sense rather than 2 drive-trains and the associated weight. Maybe this combined with an ultra-capacitor (or other cutting edge storage device yet unspecified ) to potentially capture some of your braking energy would make current hybrid drive-trains look like an "Adam Computer" i.e. a product that was neat, but who's time has come and gone.

I look forward to the day when a "super-light" something akin to the Edison X2 goes head to head against a comparable Hybrid.


eAssist can charge at stop lights and provide energy for take off acceleration. This may not be as good as start/stop but it saves wear on the engine and starter while providing some regenerative braking.


can I buy these for my current car? Since i'm a hypermiling freak I could cycle these batteries all day and all night :D

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