Jumper cable
5 Answers
may have the cables reversed
If you have negative and positive connected correctly, You left something on on the car with dead battery or there's a short somewhere
Put the jumper cables down and step away from the vehicle. Get help from someone that knows what they are doing.
If its a big spark, its usually because whatever caused the battery to go dead is still turned on... like the headlights for instance. Make sure headlights, heater, radio are turned off. Then make sure the cables are hooked up correctly, negative to negative, positive to positive, and yes, there's sometimes a small spark when you hook up even then, but it should only be a very small one.
Always connect the ground jumper cable to the CHASSIS of the car you are jumping away from the battery area. Connect it to an alternator bracket, engine block, grill support, etc and make sure it is grabbing good metal - not paint. This will minimize the chance of exploding the battery.
