Ernst Waldemar Jungner (June 19, 1869 – August 30, 1924) was a Swedish inventor and engineer. In 1899 he invented the nickel-iron electric storage battery (NiFe), the nickel-cadmium battery (NiCd) and the rechargeable alkaline silver-cadmium battery (AgCd). As an inventor he also fabricated a fire alarm based on different dilutions of metals. He worked on the electrolytic production of sodium carbonate, and patented a rock drilling device.
Ernst Waldemar Jungner was born in 1869 in Västra Götaland County, Sweden. His parents were ministers, and his father died when Waldemar was 13 years old. In 1869, the year he was born, failed harvests caused famine throughout Sweden, which affected Jungner's health. He also contracted measles and scarlet fever.
He attended Skara upper secondary school, and studied chemistry, mathematics, astronomy, botany, geology and Latin at Uppsala University. He went on to carry out further studies at the Royal Institute of Technology (KTH) in Stockholm.
In 1900 he started the firm "Ackumulator Aktiebolaget Jungner". There was a long patent dispute with Edison which was won by Edison in the end because he had larger financial resources. This caused serious problems to Jungner's firm. The company managed to survive by using a slightly different name "Svenska Ackumulator Aktiebolaget Jungner". By 2008 the company is now called "SAFT AB" at Jungnergatan 9 and manufactures NiCd batteries, one of the most reliable batteries.
During space missions in 1960s and 1970s it was the standard battery. On the rescue mission to Umbreto Nobile and his companions on the North pole expedition in 1928, several batteries were dropped from an airplane to supply electricity to the radio of the expedition. Only the Jungner NiFe battery worked.
Jungner joined the Royal Swedish Academy of Engineering Sciences in 1922 and in 1924 he received the Swedish Chemical Society´s Oscar Carlson Medal. Jungner died in 1924 of pneumonia at the age of 55.
- Hansson, Sven A.: Waldemar Jungner and Jungnerackumulatorn, 1963, sid. -92 : ill..  -92: ill. 0070-2528. ISSN 0070-2528 . Libris 10642464 . 0070-2528. ISSN 0070-2528 . Libris 10,642,464 .