Usually if your car's battery is flat you jump start it with jumper leads.
You can call the AA or if you have jumper lead cables you just need to charge it from someone else's that's car thats already got some charge.
Then you charge your car up. I think most people make sure their phone is charged, before they leave home and their car has got enough gas, so, same for electric cars - keep your eye on the meter.
I'm being serious though. If you going long distances with not much gas its not that advisable, most people know that!