it's normal. my nitro savage had the same thing. if you don't have the batteries and charger yet, hobbycity.com is the best place to look. the $35 turnigy charger is great and is what i use. it is very good for lipo batteries and ni-mh batteries alike. be sure to get the 5a 12v power supply for it too if you plan on plugging it into a wall. without the power supply, you will need to use a car battery or another 12v source to use it. the lipo batteries on that website are great and work great. you should get either two 2s 5000mah 30c turnigy packs, or two 3s 5000mah 20-30c turnigy packs. the 2s packs will the truck more powerful than ony nitro out there, and the 3s packs will turn your savage into an unstoppable beast.
http://www.youtube.com/watch?v=VeRysc6u_A8
They say a good mechanic only needs 2 tools - WD40 & Duct tape. If it moves, and its not supposed to, duct tape. If it doesn't move, and its supposed to, WD40.