Industrial truck, in particular a forklift, with an electric drive

The industrial truck, especially a counterbalanced fork lift stacker (1), has an electric drive system, whereby the truck has a power supply unit (2) constructed as an autonomous module which comprises a hybrid drive unit with a battery and a current generator. The module (10) for exchange can be installed and removed through a side opening (4) in a housing space (3) in the truck. The current generator comprises an electric generator driven by an internal combustion engine or may be constructed as a fuel cell.