Using this charger is easy. First, make sure the input power source is 240V AC. Then, connect the charger to your sealed lead - acid battery using either the lead with alligator clamps or the fused lead with 8mm ring terminals. The red light on the charger will show that it's charging. When the light turns green, it means the battery is in the trickle - charge state. Be careful not to use this charger as an AC/DC adaptor for operating equipment. Also, check the polarity before connecting to avoid reverse - polarity situations. For maintenance, keep the charger in a dry and cool place. If you notice any issues like strange noises or the light not working properly, stop using it and consult a professional.