This instructables shows how to convert your remote control car to use one rechargable and long lasting battery. This less expensive retail store bought model uses 6 AA batteries that require constant replacement. This instructable can be applied to any remote control car the only variation being the voltage, addressed in another step.
Reassemble body and drill hole for battery wires. Solder battery connector that matches the connection type of the new battery.
Rechargeable batteries vary in voltage, current, type and size.
This particular RC truck used 6 AA batteries which means that they control board has voltage regulation and circuitry engineered for 9V. The servo and motors are also designed for 9V. AA batteries are 1.5V. 1.5V x 6 = 9V. A 8V NiMH was chosen for this application.