One of the first users was a doctor in Sweden. Unfortunately, the phone needed so much power that he could only make two calls before the battery went dead. The first to his patient, and the second to the garage to get someone to come and fix his flat battery. By the mid-1960s phones were small enough to fit into the front of a car, but unfortunately, they were still too heavy for people to carry around. They were also extremely expensive. So, it was no surprise that they didn't become popular.