No, that doesn't seem normal to me. Depending on the tank , it's weight, and the type of battery you are using all factor in on run time. My mostly metal Taigen tanks will run a good half hour on a 2000 mah lipo battery. My Tamiya tanks will run longer due to the fact they are lighter. Even with nimah batteries I get a good 15 to 20 minutes. I use a Traxxas battery charger that will charge most types of batteries.