One of the linked stories [1] talks a bit about the dry cell batteries the phones used, and even mentions they sometimes used old car batteries [1] https://www

One of the linked stories [1] talks a bit about the dry cell batteries the phones used, and even mentions they sometimes used old car batteries [1] https://www.inc.com/magazine/19970615/1416.html https://www.inc.com/magazine/19970615/1416.html