How much coal does it take to charge up an electric car overnight?

How long does it take to charge a 6 cell 7.2V 3000mAh niMH rc car battery useing a charge rate of 4 amps?

• Answer:

  If a 3.Ahr battery takes a 4.A charge, something is wrong. Over charging destroys the battery. Heat is the biggest enemy, make sure it does not overheat. In theory, charging a 3.Ahr battery for 1 hour at 3.A would complete the process. It might explode in an hour. Did you mean .4A? The safest charge possible would limit the current to.1 or .2A, 200ma. As the battery reaches the fully charged state, the charging rate would go down, meaning that to top it off requires a few more hours. If you have a specially designed quick charger, (made for that battery), you'll shave off a few hours, but my guess is 12+ hours @ trickle charge, 100ma is the safest.