Market for electric cars

Suppose that in the market for electric cars there are two simultaneous changes that occur. A new technology lowers the costs of the batteries included in electric cars. Also, the price of gas powered vehicles, a substitute for electric cars, falls substantially. What is the impact of these effects on the market for electric cars (depict each separately)? (Note: one relates to demand and the other to supply, the answer to this question is about the net outcome of both effects.)