Do electric car batteries lose their stored energy over time?

Suppose I drove my electric car to the airport and parked it normally. I’ve gone for two weeks. When I get back, will be battery be dead? Do electric car batteries lose power over time? How much time?

Consider your cell phone. You have to plug it in overnight – if you don’t it will have nothing left by the middle of the next day. Of course, cellphone batteries are smaller than electric car batteries, but the principle is the same.

Contrast that to a gasoline engine. I can (and have) left my internal combustion engine car at the airport for two weeks, and with regular gas, it starts right up, so I can drive home.

Would an electric car, sitting idle for two weeks, still have power?