There are some tests on XTAR 18650 4000mAh and 26650 6000mAh batteries. Feel free to check more details via the videos below. From the tests, these batteries are true rated, ideal for dive lights!
https://www.youtube.com/watch?v=A7ojmBYMwjg
https://www.youtube.com/watch?v=A_DGkWXCyJ4
https://www.youtube.com/watch?v=A7ojmBYMwjg
https://www.youtube.com/watch?v=A_DGkWXCyJ4