The invention relates to a battery cell (2), comprising a cell housing (3), in which an electrode unit (10) is arranged, wherein the electrode unit (10) has an anode (21) which is in electrical connection to a negative terminal (11) and a cathode (22) which is in electrical connection to a positive terminal (12). The cell housing (3) includes a first housing part (61) which forms the negative terminal (11) and a second housing part (62) which the positive terminal (12). A filling opening (92) for filling a liquid electrolyte in the cell housing (3) is provided. The electrode unit (10) is heldby a retainer (82) in the cell casing (3), which is shaped such that a retention space (90) for receiving the electrolyte is formed between the electrode unit (10) and the cell casing (3).