“Fake” eh…… Depends on what you consider fake. There are a bajillion ‘clones’ of premium flashlights out there (A lot of them are great quality). If you take your time and research you should be fine.
Personally, I would go with Panasonic 3400mAh NCR18650B Protected. The only negative is that they are long and you need to check to make sure the flashlight you’re getting will fit them. I would check this thread out.