Shot a Wisconsin whitetail around 7:30 AM on Saturday, recovered the deer but lost the arrow (initially) due to a clean passthrough and the arrow burying in the dirt at an angle. Temperature dropped below freezing that night. I came out the next morning before dawn to try and fill my doe tag, and recovered the arrow because the nock was still lit. Later swapped out the nock for a new one and turned the light back on, and it took well over 8 hours before the light went out. Good to see a product that exceeds the specification by a comfortable margin.