alphacat92:
...what is the difference between the open circuit and short circuit voltage...When I connected the Peltier between Vin(-) and ground, I did not get any readings - current and voltage both hovered at around 0.
It was only when I connected the Peltier between Vin(+) and Vin(-) that I got any readings...
Open circuit voltage and short circuit current.
The first one is without load, like a 9volt battery is 9volt when nothing is connected to it.
The second one is the current it can produce when shorted. That might be 250mA for a 9volt battery.
In both situations there is no power generated into a load.
9volt * 0Amp = 0watt, 0volt * 0.25Amp = 0watt.
But you have a general idea about the capabilities of the power source.
That battery might be able to produce max power at ~100mA current, while it still is able to maintain ~6volt.
You have to experiment with the load, to find a Max Power Point (known as MPP in solar systems).
This is the same for a Peltier element.
Maybe the polarity was wrong (heat on the wrong side or Peltier wires needed swapping).
You would only get voltage readings here.
When connected to V+ and V-, you will only get current readings.
Leo..