I need the circuit....I find and test a lot circuit from online, but i still unable to get a proper solar 1.2V LED monitoring battery charging circuit. I hope someone help me solve my problem, thank you very much

my solar panel is around 3-8V input
rechargeable battery AA/AAA 1200mah/3000mah

 

I'm not sure what you mean by 'monitoring', but I think you're looking at converting the solar output into battery charging current
There are a number of switching buck regulators that can do this, with a minimal component count. A cheap regulator is the LM2576-Adj (find data sheet here: http://www.ti.com/lit/ds/symlink/lm2576.pdf). You can set it up to convert your solar panel output down to a steady 1.20-1.25 volts (from 3-8 volts), and the output can be as much as 1 amp/hour (assuming your solar panel can output that much), which would charge your batteries nicely

 

Looks like a continuation of the OPs homework thread.

 

I'm not sure what you mean by 'monitoring', but I think you're looking at converting the solar output into battery charging current
There are a number of switching buck regulators that can do this, with a minimal component count. A cheap regulator is the LM2576-Adj (find data sheet here: http://www.ti.com/lit/ds/symlink/lm2576.pdf). You can set it up to convert your solar panel output down to a steady 1.20-1.25 volts (from 3-8 volts), and the output can be as much as 1 amp/hour (assuming your solar panel can output that much), which would charge your batteries nicely

Actually i wish to have a circuit which can show the charging status of battery.
For example:
1) fully charge - LED off, charging - LED on
or
2) fully charge - Red LED on, charging- Green LED on

 

I'm not sure what you mean by 'monitoring', but I think you're looking at converting the solar output into battery charging current
There are a number of switching buck regulators that can do this, with a minimal component count. A cheap regulator is the LM2576-Adj (find data sheet here: http://www.ti.com/lit/ds/symlink/lm2576.pdf). You can set it up to convert your solar panel output down to a steady 1.20-1.25 volts (from 3-8 volts), and the output can be as much as 1 amp/hour (assuming your solar panel can output that much), which would charge your batteries nicely

what can I say?

 

sad... unable to build the circuit