How is the battery of a hybrid car charged?

What about the engine brake of an electric car, if the battery happens to be completely charged?

• Modern electric cars are able to convert kinetic energy into electric energy to recharge the battery (recuperation). So if you take the foot off the pedal, the car slows down significantly and recharges the battery. But where does the car leave the surplus of enery if the battery happens to be fully charged? How can one travel downhill for a longer distance if the battery is not able to take additional charge? Simply braking the car with its conventional brakes may result in an accident.

• Answer:

  There is no engine brake when the battery is fully charged. The engine brake gradually becomes available as the battery discharges. Some trains have heat resistors on the roof (cooled by the wind resistance), where the energy is wasted so you can have electric braking. On electric cars I don't think the added weight would be good for them. With an electric car you have to plan ahead. If you know you are immediately going to go downhill after charging, you can't charge it to 100%. Nissan Leaf has two preset modes, either 100% or 80%.