Is it possible to charge batteries using low power (0.5 mA and 0.2 V) and if so how?

Answer 1

The 0.5 mA is pretty low current, but the real problem is the voltage.
A typical 12 volt battery charges at 13.8-14.2 volts - and 0.2 volts just isn't going to cut the mustard - even on a 1.5 volt battery.
If you step this voltage up, say, 65 times (to 13 volts) - the amperage will be approximately 0.008 mA. Certainly not enough to be an effective charging devise.

Answer 2

You need a voltage pump that will raise the voltage supply above that of the battery. The current will be so low as to take a long time.