A very rapid green flash (strobing) indicates that the charger is in "Refresh Mode" for NiMH batteries. This mode is not automatic; you must insert the battery within 5 seconds of plugging in the charger.
If you have lost your manual, the LED light is your only interface. Here is the decoding chart straight from the Bosch service handbook. bosch kl 1208 battery charger manual exclusive
, allowing it to work worldwide without an additional transformer. Indicator Functions A very rapid green flash (strobing) indicates that
As the battery reaches capacity, the internal resistance increases, and the Bosch KL 1208 will automatically "taper" the charge. You will see the ammeter needle slowly drop toward zero. Here is the decoding chart straight from the
Check battery electrolyte levels (if not a "maintenance-free" type). Clean battery terminals to ensure a solid connection. Connection Sequence Connect the Red (+) clamp to the positive battery terminal.