[SOLVED] Is this Float charging can function well ? how come my NiMH's voltage dropping.

[tengyy]

AA 1.2NiMH battery

 

[Vbase]

R1 is spoiling your circuit, link it. The LM317 regulates 1.2V between out and adj diffrent charge currents wont switch off at the same voltage.

 

[tengyy]

R1 is spoiling your circuit, link it. The LM317 regulates 1.2V between out and adj diffrent charge currents wont switch off at the same voltage.

In your opinion, what is the resistance's value should i put ?
actually this circuit is from following website: http://www.next.gr/circuits/float-charger-for-nimh-cells-l36200.html

 

[Vbase]

As I suggested before, put a link (0 ohm) in place of the resistor.
You don't need R1 to limit the current because you have Q1 and Rcl already doing it.
This resistor is used to make the LM317 a current source but you can't have voltage regulator and current source at the same time.
The internet is full of circuits that don't work, you haven't discover the first one.

 

[Audioguru]

You do not need to float charge Ni-MH batteries anymore. Today they come pre-charged and hold the charge for a year.