Lithium ion rechargeable batteries, the CGR17500/18650 and CGP40488, were developed in 1994 when there was a growing need for ever smaller and lighter storage batteries that could be used for ever longer periods of time, in line with the search for more convenience in portable devices.
Responding to the needs of the time, the company developed these lightweight "lithium ion rechargeable batteries" that offered a high voltage (3.6 V). They were very much superior in the flatness of the discharge voltage, with the electric capacity and energy density being the largest in the industry. They were developed as a power source for portable devices, including high performance cellular phones and video cameras. A total of three varieties were marketed including cylindrical and rectangular types.