Most people that run their cars with any frequency buy a Nimh receiver pack for their car. You have to find a configuration that will fit into the space on your particular car. Several companies sell them, such as Reedy, Trinity, Promatch, Orion, or in one case, I went to Fry's electronics and bought batteries and shrink wrap and made my own. Remember that alkalines are 1.5 volts and Nimh are 1.2 volts. That is why there are 5 cells in receiver packs. If you have a local hobby shop that sells RC cars, they should be able to help you with this.