Are cr2016 and cr1616 batteries the same size?If they are would a 2016 battery fit in a 1616 battery holder?Or the other way around
No, CR2016s have a larger diameter (20mm vs 16mm).
It may be possible to use a CR1616 in place of a CR2016, since they have the same thickness and discharge current, but it's better to use the recommended cell.
Cr1616 Battery Cvs
the size codes are simple. CR 1616 is 16mm diam and 1.6mm height, CR 2016 is 20mm diam and 1.6mm height.
the voltages are the saem for all , the thicker ones have better battery capacity
Energizer shows the 1616 is 16mm diameter, the 2016 is 8mm. Thickness is different too. Not interchangeable.