i can never start up my bit when i put the car on the charger it would work good then after not using it for 3 to 4 hours i would want ot race it and it wouldnt start not even on the charger i tried a new battery and it worked fine but then in 3 to 4 hours it wouldnt work i tested on my friends microsizer if it was the battery but it wasnt can anybody help me please