In 1987, Nokia launched its first handheld mobile phone, the Mobira Cityman.

This beauty may have cost four and a half thousand dollars, but it still took six hours to charge and packed just a single hour of battery life. Nickel-Cadmium battery was used in the device. but suffered from the Memory Effect.

It also suffered from the Memory Effect which meant that it had to be fully used up before being recharged, otherwise it would remember the shortened charge cycle and last for even less than an hour. It was also hot and changed shape when you used it for a longer time. Add to that the toxic nature of cadmium, and it was clear something better was needed.