Before use, ensure the charger and battery are in a well-ventilated, moisture-free area. electronic power systems pty. ltd. Check Battery Fluid
The manual begins with standard but vital warnings: Bosch Kl 1208 User 39-s Manual
: For standard (non-sealed) batteries, unscrew the filler caps and check the fluid level. If the plates are exposed, top them up with distilled water until they are covered by about 5 mm of fluid. Before use, ensure the charger and battery are
Before charging, ensure the environment is dry and well-ventilated, as charging can generate explosive gases. Internet Archive (https://archive
The manual clearly warns against moisture — this charger has ventilation slots, and water inside can cause short circuits or electric shock.