You have to always consider the Earth's resources. The more batteries you make the more of that material it takes to make the battery is used up. Presently you can reuse the lead from the lead acid batteries. There is not a good method to recycle the Lithium - Ion batteries or Ultra-Capicitors at this time. Small Ultra-Capacitors will be used with Fuel Cells. Hydrogen mixed with air = energy. You would need to rebuild the Fuel Cell by replacing the Carbon Membrane every so often. Look for mini pop up air turbines on cars in the future for re-gen energy. Always remember the some of our resources are limited and this is one main reason why Fuel Cells are slow to kick off. They were using Platinum on the Fuel Cell membranes and Platinum is a very rare metal. They are now using other plentiful metals such as nickel for the membranes, even though its not as good as platinum for the anode and cathode conversion.