So how should you charge those batteries of yours? Whether sport packs or high cost race packs theirs a wrong way and a right way to charge batteries. We want the right way.
     First, you need to find a charger that suits your budget. I suggest a peak charger that includes a discharge function. This  way you can leave you batteries alone without worrying about a battery melt down. A discharge around 10amps is best, lower  is ok but not preferred by many. If  your charger has a mode where it will discharge and peak charge all by itself that's great! If you use a timed charger always monitor the packs for them to become warm. If you don't have a discharger you can go buy one. A bulb discharger is great, you can even make one.                   
Here's a homemade Battery Bulb discharger
     An average charge rate is 4-6 amps for Ni-Cd and 2-4amps for Ni-Mh. If you charger has a cycle or memory eraser mode us it when you see that your battery. Is losing its life. It can sometimes bring the battery out f the grave. I would never cycle Ni-Mh batteries. Its really easy to charge R/C batteries but it does take patience and a little getting used to. If you cant stand it you can always move to Nitro!                                    
 Don't do this to your batteries:
    This happened because of an accidental dead short
Look at this mess of old batteries. There dead. Always recycle Ni-Cd battery.
Below, these are alligator clips. They hook up to everything.