Using the Makita DC18SD fast charger is easy. First, make sure the charger is connected to a 240V power source. Then, simply insert your 14.4V or 18V lithium - ion battery into the charger. The charger will start working right away and charge your battery quickly. When it comes to safety, avoid using the charger in wet or damp places. Also, don't touch the charger with wet hands. For maintenance, keep the charger clean and free of dust. If there's dust on it, use a dry cloth to wipe it off. Periodically check the power cord for any signs of damage. If you notice anything wrong, stop using the charger and get it checked by a professional.