Moteino (8Mhz) VIN vs 3v3

[ssmall]

I am using a Moteino (8Mhz) for a project I am working on and I have a question regarding how to power the Moteino.  I am using 2 AA batteries and I initially connected power to GND and 3v3.  The reason I did this is on the Moteino (8Mhz) page there is the following statement:

The VIN and 3v3 pins are connected and can be considered the same

When I connected power to GND and 3v3 the Moteino works as expected, but the battery life is such that it would only run for a few weeks max.  When I power the Moteino via GND and VIN I am seeing the battery life that I would expect.  Should I assume that the correct way to power a Moteino (8Mhz) and get good battery life is GND and VIN?

Thanks

[Felix]

That resistor connects the pads of the input and output of the LDO (which is not there).
You can see the traces are connected together through the 0-ohm resistor. Also if you take a continuity tester VIN and 3V3 will beep.
I would expect the same behavior either way.
Do you just "wait" to measure the battery life?
I suggest doing an actual measurement through a current meter instead so we know we're comparing apples 2 apples (and for instance potential code bugs that keep mcu awake after some event don't interfere). That would also help reveal such bugs if any.

[ssmall]

I performed a continuity test between VIN and 3v3 and there is less than an ohm between the two.  I should have been a bit more precise about the pins I used to power the moteino.  I used GND and 3v3 that are on the opposite side of where you hook up the FTDI adapter.  There are 3 pins: GND, 3v3 and AREF.  I did a continuity test there between 3v3 and VIN and there is less than an ohm between the two pins.

I am measuring the voltage in the sketch once every 10 min and sending that off to my Pi Gateway. The sketch spends all of its time sleeping.  I am measuring bandgap voltage by using the technique WhiteHare published here: https://lowpowerlab.com/forum/projects/a-solar-supercap-powered-moteino/msg18027/#msg18027

I can post the code if you wish.  Like I said, switching things around to how I normally power a moteino resolved the issue, GND and VIN.  I just thought I would ask the question.

[Felix]

Both 3v3 pins are connected through traces and vias. That said, I would not use the 3v3 on the 3 pin header on far right of the board as INPUT, only as output.
I would power the Moteino 8Mhs through GND and VIN (or 3v3 next to it, same thing).

[ssmall]

Very good. That is what I'm doing and I'm getting much better battery life.