How many watts of electricity can one apple produce?

1. Watts per second
2. How long would it take to completely charge an iphone
3.Is it faster or more efficient than a regular charger?

8th grader

Revise your basics. "Watts per second" has no meaning.

Used as a battery (cell) the apple is not much of a battery. The power in watts is volts x amps (measured together at the same time). This is probably only a few milli-watts (thousandths of a watt). The energy is watts x seconds = joules. Therefore joules are watt-seconds, and watts are joules per second. There are no watts per second really.

There are a few issues:
1) The voltage would be low, probably around 0.5V, and need some sort of voltage converter to get sufficient voltage to charge the phone battery. This may be impractical because the power is so low.
2) the power is so low, it would take a very long time even if some converter were possible, and may even be insufficient to overcome the self discharge of the battery, even when the phone is not connected.
3) the energy is low, because the power is low, and the time it will eventually run for is limited I expect.

More apples in series increases the voltage. More in parallel as well, increases the current. However the power from each one is so small that even with 100 it will be very disappointing. A phone battery is probably a single lithium cell that needs about 4V and a current approaching one amp for about one hour to charge it. This amounts to approx 4 watt-hours of energy, or (4W x 3600 seconds), in joules.

How to make a better cell and battery than an apple cell:
This is not easy at home. Basically it needs suitable materials for the electrodes and electrolyte to get a higher voltage, and these should have a large surface area to increase the current. The mass of the active materials relates to how much energy (big is best). There are issues with toxic and messy materials. It will almost certainly need several cells in series for sufficient voltage to charge a cell phone. Most of the likely simple battery materials seem to deliver around 1 volt. You can try carbon and zinc electrodes with a variety of electrolytes. One of the problems is polarization. The electrode gets covered in tiny bubbles. That is why we buy ready made ones basically.

Perhaps the Daniell cell is one of the more likely candidates:
http://en.wikipedia.org/...niell_cell
http://www.make-digital.com/make/vol27/?pg=172#pg172
Read these two links and search for instructions on Youtube.