XR-E with CR2032?

Has anyone attempted running a XR-E with a CR2032 button cell? Does anyone have any idea about (or can calculate/approximate) the run time one can expect with a single 2032? Does one need a resistor when direct driving a XR-E powered by a 2032?

Hi, it is an interesting cell.

In general
- Step 1 - is the V battery higher than Vf of the LED over most of its discharge ? If yes, then you can probably direct drive / resistor it.
- Step 2 - what is the mah rating of the cell ? That rating is commonly performed at about 1/10th of its rating. ( for instance, a 100 mah cell is nominally tested at 10 ma discharged for 10 hours)

Duracell and energizer have very decent data sheets on their cells so you can find this info from their web site.

- Step 3 - Pick how many ma you want to drive your led, ideally so that the cell discharge is at least 1/2 an hour.

Question - is this enough power for your desired setup? If not, try the next cell until you are happy.

You could use 2 2032 in series on an xre properly heatsinked easily without a resistor. I doubt you would even approach 250ma off 2 in series and probably not even 100 driving it with one cell due to the high internal resistance of the cell will cause voltage sag at higher currents.