These batteries were common and available in the 1940s for a number of different appliances. However, they are now very rare as once they were used up, they were thrown away. It is even harder to find an Enigma machine with an original battery still in place. These batteries can deteriorate and leak over time, causing damage to the Enigma. For instance, in some relic Enigma machines there are holes near where the battery box sits, showing the effects of battery acid on the base of the Enigma machine.