For a scanned copy of the official 1‑page datasheet, search: "Bosch KL 1206" site:bosch.com file:pdf
If DF to D- is short (0Ω) or open (∞Ω), regulator is defective.
Plug In the Charger: Connect the Bosch KL 1206 to a standard wall outlet.
This charger will not turn off on its own. You must manually unplug it to avoid "boiling" the battery or causing a fire.