Charge a Li polymer mobile battery from 7 V current in few milliamps

[live1729]

Hello everyone,  I have a source that produces nearly sinusoidal output voltage at separation of 500 ms, for 500ms, It is like an output one will get when a 40 Hz sine wave is multiplied with a 2 Hz square wave (0-1V) or a 2Hz clock signal. The amplitude of alternating output is almost 5-7 V pk-pk.

This output is to charge a Li polymer battery(3.6 V). The output is being converted to DC by a voltage doubler rectifier using low drop schottky diodes. And the output of voltage doubler has capacitors. I am getting about 6-7 V across these capacitors. A charging circuit has to be connected between these capacitors and battery.

What sort of charging circuit can I use with such output to charge standard Li polymer battery of a mobile.  The current that I am getting is only few milliamps, on a raw test by directly connecting battery. Is there any way to reduce dc volt to say 4-5 V and increase the current by some amount.

Please reply soon, have submission soon

[live1729]

This is the initial circuit i tried in multisim, after these capacitors i want to charge a li polymer battery from the charge stored in capacitors. Ignore the 0.5 V showed on source. Consider its amplitude 5 V pk-pk. Or 2.5 V 0-pk.