hey, my hpi bullet 3.0 with the 2.4ghz radio ranaway for the 4th time. I'm so sick of it and this time it hit a bolder and destroyed my bumper set and caved in the shell. I called hpi and complained and they are sending me a new receiver, a new throttle servo, and a new front end bumper free of charge, love hpi for tht. Any how it seems to happen with crap batteries and its pissing me off. did i have a defective receiver or do i need to invest in rechargeable battery pack? if so what battery pac should i get?