Polarity check: To protect the charger from connecting the wires in the wrong order (+/-), the charger is equipped with a fuse that will blow if the wires are connected in the wrong direction. The fuse is located in the drawer on the chargers power cable side and should be replaced there with a new one of the same power. The battery charger is intended for use only in dry conditions away from water and moisture. The charger is equipped with three indicator lights:1. The red “Power” indicator light indicates that the charger is connected to the mains.2. The yellow “Charging” indicator light indicates that the battery is being charged.3. The green “Fully Charged” indicator light indicates that the charging process is complete and the battery is fully charged.  Instructions for use:1. Make sure that the charger is not connected to the mains.2. Connect the red wire to the batterys positive (+) terminal and the black wire to the batterys negative (-) terminal, and then connect the charger to the power supply.3. The charging process is indicated by a yellow indicator light.4. When the charging process is complete, the green indicator light will light up. Unplug the charger from the power supply and disconnect the battery from the charger, first the red positive wire and then the black negative wire. Technical data: Input voltage: 230V 50Hz   Charging current: BasicCharge4             4amp (RMS)     2.7amp (DC)   BasicCharge6              6amp (RMS)     4amp (DC) Charging voltage: 12V DC   Battery types: Lead acid batteries   Battery capacity: BasicCharge4             20AH – 50AH   BasicCharge6 20AH – 70AH Dimensions: 215 x 80 x 180 mm   Weight: 1.77 kg   Protection: BasicCharge4 5amp fork fuse   BasicCharge6                         RECB104   BasicCharge6                      RECB106