Method for Operating an Electrical Stored Energy Source, and Electrical Stored Energy Source

A method for operating an electrical stored energy source having a housing and at least one storage cell which is situated inside the housing. The method includes: first, a malfunction of the at least one storage cell and/or of the electrical stored energy source is determined, in which malfunction a fuel gas-air mixture is formed inside the housing. Then, inert gas is metered into the housing by a metering device of the electrical stored energy source, wherein sufficient inert gas is metered into the housing that the oxygen concentration inside the housing assumes a threshold value. The oxygen concentration is detected by an oxygen sensor of the electrical stored energy source. The threshold value is less than or equal to the oxygen limit concentration, which is defined as the maximum oxygen concentration at which combustion of the mixture of fuel gas, air and inert gas in the electrical stored energy source is not possible.