I bought a Rustler XL-5 couple weeks ago. I bought a Piranha Intellipeak Charger and GP3300 battery from Radio Shack, and a 4200 Dynamite pack. Both 6 cell. I am charging them both to peak and my run time stink. Some guys are telling me they are getting almost thirty minutes of run time and I am getting like ten on the 4200, and even less on the 3300. Should I discharge these batteries? I though discharging NIMH was bad to discharge? I am using 3 amps for charging....Any recs?