DETROIT – Fueled by the new Insight and at least two more models in the pipeline, Honda Motor Co. Ltd. hopes to boost annual hybrid sales to 500,000 units in 2015.

In 2008, the auto maker sold 57,000 units, mostly Civic Hybrids, with several hundred Accord Hybrids.

If Honda achieves its target, hybrids will account for an estimated 10% of its global sales, says Yasunari Seki, the Insight’s chief engineer.

Seiki reiterates in an interview the auto maker plans to introduce a hybrid sports car in 2010. Then, probably in 2013 – although he would not confirm a launch date, Honda will follow with a hybrid version of the Fit, which may or may not be sold in North America.

The sports car will be based on the CR-Z concept unveiled at the 2007 Tokyo Motor Show. Seki notes the production model will be equipped with the same motor and battery as the Insight but boast a more powerful engine, most likely displacing 1.5L. The Insight has a 1.3L engine. The CR-Z powerplant will not be turbocharged, he says.

Seki indicates the Fit Hybrid will employ the same single-motor system as the Insight, although most likely an improved version.

In developing the current model, Honda reduced hybrid system size and cost 30% and 40%, respectively, from that of the Civic Hybrid. The auto maker’s 5-year development target is for a further 25% size and cost reduction.

Including the Insight’s 101-volt nickel-metal-hydride battery pack, the Insight’s integrated motor assist (IMA) hybrid system weighs 128 lbs. (58 kg), 20% less than the Civic Hybrid system at 158 lbs. (72 kg).

Seki doesn’t confirm the cost of the Insight’s hybrid system, but does concede it is in the range of ¥100,000-¥150,000 ($1,000-$1,500).

The chief engineer notes the Insight’s model life will be five years and that Honda will have five hybrids in its lineup by 2015, meaning the Insight is likely to undergo another model change in 2014.

Meanwhile, he says no decision has been reached regarding Honda’s plans to switch to a lithium-ion battery pack from NiMH. But by making that move, he says, the auto maker would be able to cut battery size and weight in half, as Li-ion has twice the energy density of NiMH.

Bringing down battery costs is another matter, according to Seki, and will depend in part on increasing production volume.

On April 1, Honda entered into a joint venture with a subsidiary of GS Yuasa Corp. to develop and manufacture Li-ion batteries for hybrid vehicles. GS Yuasa says production startup is scheduled for 2013.

The battery will be based on GS Yuasa’s EH6 unit rated at 6 ampere-hours with energy density of 67 watt-hours per kg.

Separately, Tomohiko Kawanabe, a senior managing director at Honda R&D Co. Ltd., notes engineering targets for Li-ion batteries are between $500 and $800 per kWh, down from current $1,000-$2,000 levels. “I think $50 is necessary, but it is difficult to say when that can be achieved,” he says.

Seki also confirms Honda is developing a 2-motor hybrid system – although not necessarily the same concept as used by Toyota Motor Corp.’s Prius. However, the auto maker has no immediate plans to introduce such a model.

Nevertheless, the chief engineer believes 2-motor systems hold potential for larger vehicles, such as the Ridgeline pickup or Odyssey minivan. “We think the technology is good for fuel economy,” he says.

But a 2-motor setup is less viable for smaller cars, such as the Fit, Insight or Civic, due to packaging constraints, Seki contends. The Prius battery and motor-generator are 2.5 times larger than that of the Insight, he notes.

Concerning mild hybrid stop-start systems, Seki hints Honda is considering such technology for its minivehicle lineup – currently comprising such 0.66L models as the Life, Acty, Vamos and Zest. He gives no timeframe for such a debut, however.

Honda does not include stop-start systems in its hybrid sales forecasts.

Seki is confident Honda will meet the Insight’s 2010 sales goal of 200,000 units, although last December Honda CEO Takeo Fukui cast doubt on whether the target would be reached. And while Seki predicts North America will be the Civic Hybrid’s main market, he believes the Insight will make inroads into Europe, where Honda is projecting 2010 sales of more than 30,000 units.

In addition to Europe, Honda hopes to sell 100,000 Insights in North America (including 90,000 in the U.S.) and 60,000 in Japan.

Turning to the Insight’s suppliers, Seki confirms Sanyo Electric Co. Ltd. is producing the model’s battery pack. The unit, which like the Civic Hybrid’s 53-lb. (24-kg) pack employs 12 cylindrical cells per 14.4-volt module, weighs only 33 lbs. (15 kg), or 38% less.

The weight savings was achieved by using fewer modules – seven, compared with 11 for the Civic Hybrid. Power also was reduced as a result, from 158 volts to 101 volts.

In a technical paper presented at the SAE World Congress in April, Honda engineers say weight and volume of the power control unit was reduced 31% and 10%, respectively, by integrating the inverter, DC-DC converter and electronic control unit into a single package.

Specifically, the Insight’s inverter is 36% lighter and 35% smaller than the Civic Hybrid unit. The DC-DC converter is 46% lighter, largely the result of making the heat sink smaller, while the auto maker trimmed motor weight 15% by downsizing the stator and rotor yoke.

Other suppliers include Keihin Corp. (battery ECU, engine and transmission ECU and motor power drive unit), TDK Corp. (DC/DC converter) and Mitsubishi Electric Corp. (motor inverter).

Honda produces the Insight’s Multimatic S-CVT continuously variable transmission at its Hamamatsu, Japan, plant.

The auto maker assembles the hybrid’s 1.3L gasoline engine, motor and intelligent power unit on sublines in its Suzuka, Japan, facility.

A new motor line, which began operation in November, has capacity for 180,000 units, raising total motor production capacity on the plant’s two lines to 250,000.

Seki notes the auto maker has tripled motor production speed by improving winding operations and other processes.

Honda also manufactures the Insight’s regenerative braking system in-house, although sources say the car’s main braking system is from Continental AG.

The auto maker estimates 36% of Insight components are carried over from the Fit, Civic Hybrid and other models.