Zebralight is not one to overstate their lumen ratings. They are usually very close to the mentioned ratings. You either have an issue with yours, or somthing is funky with your battery. Check the stamped date on your Eneloops on the side of the battery and do a capacity test to see if the cell or cells from the pack don’t have issues or are old. Your going to need a really fresh/healthy cell to pull the claimed lumens.