the stock tomy batts are NiCad. NiCad's have a power memory problem...so, if u've never fully charged the batt and fully discharged it, the battery has a very short lifespan. [does that make sense
] basically you may need to replace the batts inside the car.
and...the 45 sec charge on the controller does not fully charge the stock battery. Read something about that on the peak charG thread in this forum