The motor on the front wheel (left) and the Li-ion secondary battery (right) located below the saddle. The motor functions as a generator and regenerates electric power when going downhill and braking.
Sanyo Electric Co Ltd will release an electric hybrid bicycle that is equipped with a Li-ion secondary battery and has a twofold assist force compared with the company's previous models in early February 2009 in Japan.
The "eneloop bike (product No: CY-SPA226)" is the "industry's first product" that reflects the revision of the Road Traffic Law Enforcement Regulations enforced Dec 1, 2008, according to Sanyo. The revision increased the maximum drive assist ratio (the ratio of motor drive force to human power) from one to two in Japan. The 26-inch bicycle will be priced at ¥136,290 (approx US$1,463, including tax).
Sanyo has been selling its electric hybrid bicycles under the "enacle" brand but decided to sell the new and future bicycles that reflect the revised regulations under the eneloop bike brand name.
The motor that drives the front wheel is a brushless motor with a rated output of 250W, which is equivalent to the motor used in the company's previous bicycles. But its maximum output was enhanced to leverage the new regulations.
In addition, the rated voltage and capacity of the Li-ion secondary battery were increased by about 1.5 times to 25.9V and 6.0Ah, respectively, compared with those of the battery used in the previous models. Because of these changes, the charging time increased from two to 3.5 hours.
The eneloop bike is equipped with the "loop charge" function, which uses the assist motor as a generator during braking and downhill riding for regenerative charging. The function is also employed by the enacle, which was released in March 2008.
The new bicycle features three running modes. In the "Auto" mode, switching between assist and power generation is automatically controlled. The "Power Up" mode provides a continuous assist force that is the equivalent of twice human power. And the "Standard" mode provides an assist equivalent to human power and recharges the battery during braking.
In the Auto mode, the assisting force is adjusted in accord with running conditions. And the power generation is automatically started when going downhill, without using the brakes. The running conditions are estimated based on the rotating torque detected by a coil reactance-type sensor and the revolution speed of the front wheel, according to the company.
The cruising distance of the bike is 57km without regenerative charging while it is 75km in the Standard mode where regenerative charging occurs during braking, according the results of the running test conducted by Sanyo. In the Auto mode, the travel distance reaches 100km.
Sanyo also released a model equipped with a Ni-hydrogen secondary battery. This battery is easy to control. But the cruising distance of this model in the Auto mode is only 53km because the capacity of the battery is smaller. The other functions are the same as those of the Li-ion secondary battery model. The model comes in two sizes, 24 and 26 inches, and the prices start from ¥91,140 (including tax).
The electric hybrid bicycle market saw shipments amount to 283,000 units in 2007. Sanyo estimates the number will be 300,000 units in 2008. The company expects the market to be further grown by the new regulations because "the increased assist force makes it easier to go uphill and stabilizes the ride."