Everytime I try to charge my DS lite, I plug the charger in and it only flashes orange for a second when the charger is halfway plugged in. I have tried the charger on a friend's DS and it works. I don't know what's wrong.
Look at the small prong inside the charging port on the DS Lite. Is the prong bent out of shape in any way? Also, how heavy has the usage of the system been? If you can, try your friend's battery in your DS Lite, because your own battery may be dead.
If another battery does not work, then your DS Lite is broken, and you will need to get a repair. Call Nintendo at 1800-255-3700 (6am-7pm, Pacific Time, 7 days a week) to schedule one.
you probably need a new charger or a new battery if you got it used then the battery life is probably been used up when you get a ds or a 3ds or any ds system than understand that most ds can last up to 200 charges