The battery sparks a lot when i try to connect the cables.The poles began to fry and i need to separate them.I place the cables over the correct battery poles.If i leave them in place i can damage the battery?I have a volvo 740 1987 without turbo.Thanks for the attention.

If all the electrical gadgets and stuff are turned off in the car and the ignition switch off there should be hardly any spark as you connect the battery.

Large spark = large electrical current going somewhere.

Either something is turned on that should not be, or you have a short circuit somewhere. The battery will not be harmed by short periods of delivering large current, but it will eventually be flattened. If you have a short somewhere then when you connect the battery the relevant fuse should blow. If, however, you have a short in some part of the wiring not protected by a fuse, you could get an electrical fire.

Since pretty well everything is turned off by the ignition switch, make sure the ignition switch and the head and sidelights and foglights and rear foglights are turned off, and radio (the only things I can think of likely to be wired so as to be capable of being on when the ignition is off) and try again. If you still have a large current draw from the battery then you need to trace it and the obvious suspect is the wires going to the ignition switch.

Also if you have an ICE amplifier and/or a towbar, check the wiring to them. Some people who fit them and the associated heavy wires are really really slipshod!

might also be woth checking the wiring to the starter motor, that is really heavy duty and unfused.
Grendel