[AllyCat]

Hi,

using focusing flash light, my v+ measures at 5.4mv, while v- at 10.3mv. outputs 80.2mv, im not sure where went wrong

A flashlight is probably not bright enough. The output of a "rail-to-rail" Op-Amp cannot go absolutely down to zero volts, but 80 mV does seem a little high. But it will depend on exactly what load it is connected to. The 10 mV at the - input is consistent with that output voltage, but the PV input has not reached that voltage, so the Op-Amp cannot "balance" and amplify anything.

Is it a LED or "wire filiament" bulb in the flashlight? A filiament lamp (particularly mains powered) is generally preferable for tests, because it puts out lots of IR, which the PV panel is (or should be) most sensitive to.

If you increase the Op-Amp gain by very much, then it (or the ADC) will overload when you use real sunlight.

Cheers, Alan.